“I’m really disappointed that we don’t have a fair judgment and any justice in Hong Kong,” Lam said after he was released on bail pending appeal. “I’m not a liar. I’m not a liar. I tell the truth.”

His mother added in tears: “My son has never told a lie.”

Police subsequently spent 7,000 man hours on the first month of the investigation alone, which cost more than HK$1 million (US$128,200), based on hourly pay, officer-in-charge Emily Lau Sze-wai revealed. One officer then spent four months reviewing 1,500 to 1,800 hours of security footage sourced from shops and buildings across four districts in the city.

“The entire investigation was very difficult … mainly because it involved a lot of CCTV footage,” said Lau, a detective senior inspector.

“CCTV was very important because it proved he was never abducted.”

After a trial at West Kowloon Court, Lam was found guilty of one count of knowingly making a false report to police about an offence, which is punishable by six months’ imprisonment and a fine of HK$1,000. He had no prior convictions.

Lam’s critics also questioned the Democratic Party’s credibility since he had first gone public with the account at a party press conference attended by senior members, including Martin Lee Chu-ming and Albert Ho Chun-yan.

Ho was also present in court on Friday, joining party lawmaker Ted Hui Chi-fung and Lam’s theology thesis supervisor at Chinese University, associate professor Kung Lap-yan, who had previously testified on the activist’s good character.

The party would offer legal assistance to Lam in his appeal bid, chairman Wu Chi-wai said, adding that he respected the court ruling.

The high-profile trial centred on a police report Lam made to detective police constable Wong Kai-pui at Queen Mary Hospital in Pok Fu Lam after his August 11 press conference.

In the report, Lam claimed a mainland public security officer, named Xu Ke, contacted him and expressed dissatisfaction with his plan to give away Messi’s photo, and he was kidnapped two days later in broad daylight on Portland Street in Mong Kok.

A medical examination found he had linear bruises on his belly and 21 staples punctured into his thighs. He also had psychiatric medication such as tranquillisers and sleeping pills in his system.

But a turning point came after police viewed security cameras and found him walking freely in many clips when he had supposedly been kidnapped.

Lam was arrested on August 15, 2017.

A government forensic pathologist testified at trial that Lam’s injuries were potentially self-inflicted while the defence called British forensic physician Dr Jason Payne-James to explain his injuries were consistent with his story.

The magistrate said he had repeatedly viewed the relevant footage and observed Lam in court to conclude he was the man in black caught on camera walking around Yau Ma Tei to catch a minibus to Sai Kung, having a gait marked by his toes pointing inward.

He also observed that Lam did not show any signs of having being tortured in undisputed footage taken after the alleged abduction, which showed him buying cigarettes and food from McDonald’s and eating at a deserted car park before going home.

But So noted these clips had to be viewed together with the medical evidence, given Lam had tried to conceal his appearance by wearing sunglasses, mask and cap.

While the magistrate said he believed Payne-James was an honest witness, he eventually sided with the government’s expert, whom he said had the chance to examine Lam in person and had offered a reasonable and reliable analysis of the injuries.

“The court is certain there never was an abduction,” So concluded. “He must have known he was lying. He had orchestrated the entire incident.”