It's rare for Bruce's siblings to share a stage with his daughter or his widow, Linda Lee Cadwell.

The two sides of the family have often pursued projects devoted to Bruce separately.

What little communication there has been has more often come in the form of e-mail exchanges and letters from lawyers, rather than heartwarming phone calls and family gatherings.

"Let bygones be bygones," Phoebe, 74, said on the eve of the opening of the exhibition at the Heritage Museum in Sha Tin. "It feels so much better if you let it go ... We share the same family name after all."

The division in the Lee family is no secret. Distance (most live in different parts of the United States) is one reason. Cultural differences also come into play, with Lee's siblings forming a traditional Chinese family.

Shannon and Cadwell, who has remarried twice since Bruce's death, are all-American.

"We are not on bad terms," Shannon said. "We just don't communicate very often."

But Robert, speaking from the US, has a different take. "I wish Bruce wasn't that famous in that respect," he said. "We could have a real, complete family."

At the crux of the family feud are the lucrative rights to Bruce's name, image and work. The controversy has been reignited by the Bruce Lee: Kung Fu, Art, Life exhibition, which opens to the public today and runs for five years.

Robert said his side of the family has been shunned by organisers after they got in touch with the Bruce Lee Foundation, a charity headed by Shannon and Cadwell. "Three years ago, the museum approached me and Phoebe on the exhibition," Robert recalled, describing a lunch with Leisure and Cultural Services Department officials in San Francisco.

He said he and Phoebe even proposed installing a replica of their childhood home at 218 Nathan Road from the set of the 2010 biopic , for which Robert served as an executive producer.

The museum liked the suggestion. But he said: "We didn't hear anything from them. We didn't know what was going on."

He later realised the museum had teamed up with Shannon for the exhibition, in which more than 400 out of the 600 exhibits come from the foundation's collection. Sources say the government museum simply wanted to stay out of family affairs.

But the handling of the matter certainly upset Robert, Phoebe and their sister Agnes, who demanded the museum remove the film set just one month ago, saying they owned the intellectual property rights.

Rights issues have become an unshakable problem for the Lee family since Bruce's death from acute cerebral edema.

Records of the office of the secretary of state of California show that in 1985, Cadwell, Lee's late son Brandon and Shannon made claims as successor-ininterest to the rights of a deceased personality under California code Section 3344.1. The code offers protection of the rights to a person "whose name, voice, signature, photograph, or likeness has commercial value at the time of his or her death" for the immediate family - a surviving spouse, children, grandchildren, or surviving parent or grandparents.

Public records show Cadwell claimed 50 per cent of "all types of rights" as Lee's surviving spouse under the name Linda Lee. Brandon and Shannon each claimed 25 per cent as Lee's surviving children. Shannon was just four when Bruce died.

"We were never aware of those actions as we never bothered to check," Robert said. "Our family never knew whether he [made inheritance plans] as we never asked ... We never thought he would pass at the age of 32."

The Bruce Lee Foundation was established in 2002 as a charity to promote Bruce's legacy. Shannon serves as president and it is chaired by Cadwell. In 2008, the family's successor-in-interest rights were handed on to Bruce Lee Enterprises, in addition to rights retrieved from Universal Studios, Shannon said.

She explained that Bruce Lee Enterprises was an in-house licensing division, handling everything from T-shirts to a much-criticised commercial for Johnnie Walker whisky. The advert was premiered last week and uses computer-generated imagery and an actor to portray Bruce.

There is also the LeeWay Media Group, which handles productions such as the 2009 History Channel documentary and the 50-episode television series , aired on CCTV on the mainland in 2008. Shannon was executive producer for both shows.

The foundation is also working to raise US$35 million to build Bruce Lee Action Museum in Seattle, Shannon said.

All these structured efforts enable Cadwell and Shannon to exercise a strict control over the use of Bruce's name, image, likeness and all related material.

Bruce's siblings have no involvement with the trust. Johnnie Walker has to license the rights to digitally "revive" Bruce for the company, Shannon said.

Thus, entering legal disputes with others has become a routine for Bruce Lee Enterprises since it was incorporated. It has taken retailers like Target and Urban Outfitters to court for selling T-shirts bearing the images of Bruce without authorisation.

"The rights of the dead to keep earning are clear," attorney Oscar Michelen said in a commentary on the case on his blog Courtroom Strategy.

In 2010, Shannon brought the copyright campaign to China, accusing firms and individuals of using Bruce's name and image without family authorisation.

She also reportedly asked the local government of Shunde, a district of Foshan, Guangdong, that is the Lee family's ancestral home, to hand the trademark to Bruce's name and image to the family and the Bruce Lee Foundation for free. In June, LeeWay Media entered a copyright dispute with Laurence Joachim and the Trans-National Film Corporation, who claimed they had the rights to Bruce's first Hollywood screen test.

The eight-minute 1965 clip was featured in , a documentary released last year and produced by LeeWay Media.

And stringent copyright enforcement didn't just apply to those outside the family.

Kris Storti, chief operating officer and general counsel of Bruce Lee Enterprises, said in a 2009 press release: "We are redoubling our efforts around the world. We are absolutely committed to a vigorous protection of the Bruce Lee brand and our intellectual property, and plan to pursue legal action whenever necessary."

In reference to the film , Storti added: "This, unfortunately, includes the recently announced biopic by JA Media and Robert Lee."

Media Asia, which co-produced the movie with JA Media, and another investor received legal letters from Shannon's lawyer before the movie was released in 2010.

"[Storti told] them they did not have the right to use Bruce Lee's image or likeness," said Robert, who co-produced the film, based on stories told by him and his two sisters.

He said before the film went into production, he tried to involve Shannon by giving her the details of the investors. "Then she didn't want to work with me. She wanted the whole deal to herself," he said. "We don't talk as much as I would like to. They don't want to collaborate with us. We are one family. There is no reason why we shouldn't collaborate. We share different parts of Bruce's life."

When the Bruce Lee Club of Hong Kong, of which Phoebe and Robert are honorary chairman, raised the money for the iconic statue of Bruce on the Avenue of Stars in Tsim Sha Tsui in 2005, they reached out to Shannon. But she chose not to get involved.

"I'm not trying to take over the Bruce Lee empire," said Robert. "I will [soon] be 65 and semi-retired. I'm not interested in pursuing anything. If they think I'm trying to make money, I haven't done except for from the movie."

He says the two books he wrote about Bruce - one in Chinese, the other in Japanese - sold only 1,000 copies each.

Shannon, who plans to produce a film based on a script by her father, tells a different story.

"I hear things … like I have heard some people say my uncle claims they have certain intellectual property rights prior to the day [Bruce] married my mother.

"[Robert] has certainly never said that to me. I asked about it and he denied he had ever said that," Shannon said. "Certainly it wouldn't have been true. That's not how the law works."

Robert said: "Our family was never sued, but received threatening cease-and-desist letters from Linda's ex-attorney. I stopped talking to Linda."

Clarence, who lives in Macau and Hong Kong, said: "I'm speaking not just for this family but for any family. To speak through lawyers is kind of wrong."

He said his father and aunts were frustrated, as they wanted only to share their experiences with fans interested in Bruce's childhood. Robert recalled a family that was closer back then, supporting each other when Bruce died even though Bruce's siblings were in the US when the news broke. Phoebe moved to the US with her American-born Chinese husband 43 years ago. Robert lived in the US at the time and returned to Hong Kong in 1975 to build his music career.

When Bruce's mother died in 1996 - three years after a tragic accident on the set of the film claimed Brandon's life - Shannon, then 27, did not attend the funeral.

"They [Shannon and Cadwell] did not visit mother during her last months and they did not attend her funeral," Robert said.

Bruce's siblings say it is a far cry from Bruce's attitude to his family. Phoebe, who is two years older than Bruce, said her beloved brother made family his top priority. She remembered the delight of her father, Cantonese opera maestro Lee Hoi-chuen, when he learned of Brandon's birth in the United States.

"He was very happy because it was the first grandchild and a son. You know what a son means in Chinese tradition," she said.

One week later, Lee Hoi-chuen passed away in his sleep. Bruce rushed back from California to attend the funeral.

Phoebe said Bruce was devastated that he could not bid farewell to his father in person.

"He walked on his knees from the outside to the altar. He was in tears, and I said to him, 'Don't cry, brother'," Phoebe recalled.

Phoebe is reluctant to speak about her relationship with Shannon and Cadwell. She said she didn't really communicate with Cadwell and blamed her poor English.

She still attended the exhibition's opening last night because she was proud of her brother's achievements and is still loved by fans around the world. Robert thinks a misunderstanding must be behind the family rift, though he isn't sure what it was. "Even if something happened between my mum and Linda, let bygones be bygones," he said.

Robert will not attend the exhibition, but he has asked Clarence, 33, to speak to Shannon.

"I said to him, 'She's your elder. Go see her and talk to her'," he said.

Clarence sees the exhibition as a chance to catch up with his cousin. "She's trying very hard to promote the legacy of her father the way she wants," he said.

And Robert has just one hope left for his brother's legacy.

"I just wish one day things would work out ... I hope all this can be resolved before my two sisters and I die," he said. "Let's tear the wall down."

Video: How Bruce Lee learned to fight