Tran Thao and Tran Thu were the key witnesses in a closed-door trial in Vung Tau which saw the fallen Glam Rock icon jailed for three years on Friday for committing obscene acts with minors in a case that, on the face of it, demonstrated that Vietnam is not prepared to harbour the child sex tourists who have blighted the image of neighbouring Cambodia.

However, as Tran Thao and Tran Thu return to their families this weekend to rebuild their young lives with the help of US$2,000 pre-trial 'compensation' payouts from Glitter's lawyer, the trial has left troubling questions about whether justice was really served.

Prosecution papers seen by the Sunday Morning Post indicate that the police, after initial interviews, had a case strong enough to bring child rape charges against Glitter - an offence which carries a maximum penalty of death by firing squad in Vietnam.

The course of justice appears to have been dramatically altered by an encounter between the two witnesses, their mothers, Glitter's lawyer and a police chief in charge of the case in December, one month after the British singer was arrested as he tried to board a plane from Ho Chi Minh City to Bangkok.

Glitter, jailed in his home country in 1999 for possessing child pornography on his computer, had been living in self-imposed exile in Cuba and then Cambodia since that conviction, which saw him transformed from a fondly loved pop relic with a healthy income from nostalgia tours and royalties to Britain's best-known paedophile. Rather than seek help, rehabilitation and perhaps eventually redemption in the eyes of his fans, Glitter played the villain and chose to go on the run.

He was hounded out of Cuba, then in 2003 kicked out of Cambodia, where he owned a house in Phnom Penh, after the newspapers he saw as his persecutors embarrassed the government with largely unsubstantiated revelations that he had become a client of the country's notoriously prolific child-sex industry.

After criss-crossing the border to Vietnam as he pursued a futile legal battle to be allowed back into Cambodia, he gradually came to believe that in the oil city of Vung Tau, a mildly sleazy weekend retreat an hour's ferry ride from Ho Chi Minh City, he had at last found the haven his lifestyle demanded.

He became a regular visitor, staying in discreet mini-hotels in the town's Back Beach area and building up a small circle of star-struck, protective expatriate friends. By the beginning of 2005, he was confident enough to rent a seafront villa a kilometre from the city's busy strip of girlie bars and nightclubs and apply for Vietnamese residency. Glitter was initially careful not to draw attention to himself.

Prosecution papers submitted to last week's trial say that soon after moving into the walled villa, he hired taxis to bring three Vietnamese working girls down from the Cambodian border to visit him in his home. Bui Thi Cam Tu, 17, Tran Thi Kim Oanh, 24, and Truong Thi Bich Thuan, 24, would stay sometimes all together and sometimes alone or in twos with Glitter for up to four days at a time. He would pay them sums ranging from 500,000 dong ($245) to 3.2 million dong each.

Glitter was careful to keep the liaisons secret, even though the girls were above the legal age for sex in Vietnam. When he paid them, he would tell them not to say anything about what they had done with him. The maid at his rented house Nguyen Thi Anh testified that the girls asked her to tell anyone who made inquiries that they were in Vung Tau looking for work.

As his sense of security deepened, it seemed, his propensity to seek out sex with ever-younger girls kicked in.

Glitter persuaded Ms Oanh to bring her 10-year-old niece Tran Thu to stay with him three times in June and July. On two of those visits, according to the prosecution papers, Ms Oanh sold the petite pony-tailed girl to Glitter.

In her initial police interviews, Tran Thu told police Glitter fondled her when she got out of the shower and then had sex with her.

During her stays, she said, the three of them would sleep naked on the same bed at night and Tran Thu would be made to watch while her aunt and Glitter had sex. Ms Oanh watched on both the occasions that Glitter molested and had sex with Tran Thu, the 10-year-old told police.

After the first occasion, Tran Thu was given 100,000 Vietnamese dong by her aunt out of the 800,000 dong paid to her by Glitter and told not to tell anyone what had happened.

At around the same time, Glitter struck up a sordid relationship with orphan Hoang Thi Bong, 19, who later testified that she went to his villa for sex on around 30 different occasions. It was Ms Bong who introduced Glitter to the then 11-year-old Tran Thao in September last year and took her with Glitter to a rented room in a guest house. There, Glitter had sex with Ms Bong and stripped and fondled Tran Thao.

The following month, Ms Bong again brought Tran Thao to Glitter, this time to his home where, according to initial interviews with Tran Thao, he showed a sex video on his laptop computer to the two girls before taking them both upstairs for sex.

Glitter's depravity only ended when, after a drunken appearance at a bar near his home with Tran Thao on his arm, disgusted drinkers tipped off British journalists, including myself. When I confronted him at his home, he fled and was arrested a week later as police began investigating his activities.

Little was then known about the extent of what went on behind the walls of his villa. However, the prosecution papers show that when their interviews were complete, police concluded Glitter had had sex with both Tran Thao and Tran Thu and - even if intercourse was technically consensual - could be prosecuted for child rape because of their ages.

Glitter's destiny - and the evidence from his two young victims - changed course one day in early December at a meeting between his lawyer, a police chief in charge of the case, Tran Thao, Tran Thu and their two mothers.

Before the meeting, according to the prosecution papers, Tran Thao's mother Nguyen Thi Hong Mai made a request to Glitter's lawyer for US$10,000 compensation. At around the same time, Tran Thi Thu Yen, the mother of Tran Thu, made a similar request for US$5,000. Claims for 'compensation' from crime victims and their families are common practice in Vietnam.

At the meeting, Tran Thao's family said later, the girls and their mothers sat across a table from Glitter's lawyer and the police chief and were told that Glitter was prepared to pay US$2,000 to each of the families if they signed a sheet of paper saying they did not want to pursue the case against him.

In an extraordinary scenario related by Tran Thao's mother, envelopes filled with US$100 bills were put on the table and the police chief told them they could take the money home with them if they signed the papers immediately.

'We didn't have the opportunity to read the paper properly and we were told that we must sign the paper immediately or the offer was closed,' Ms Mai said. 'We signed because we needed the money and our families believed that Gary should pay money for what he did.'

Days after the money was handed over, according to the prosecution papers, the girls were re-interviewed.

Tran Thao and Tran Thu both contradicted their earlier testimony and told police Glitter had 'only kissed and touched' them and that no full sex had taken place.

Medical tests showed Tran Thu was still a virgin. Tran Thao was not, but when questioned by police in her later interview, she told them she had a regular Vietnamese boyfriend with whom she had sex.

Glitter's defence against the allegations was straightforward and unconvincing.

He told police he had only ever given English lessons to the girls, that he had slept in a bed with Ms Oanh and Tran Thu because they were 'afraid of ghosts'. The allegations were being levelled against him by families who wanted to extort money from him, he claimed.

In reading out the verdict on Friday, Judge Hoang Thanh Tung condemned Glitter for paedophilia.

'Caring for children is to care for our future ... but Gary Glitter's acts went against this,' the judge said.

'He sexually abused and committed obscene acts with children many times in a disgusting and sick manner.'

But Glitter was defiant to the last, proclaiming to the court after the verdict was announced 'I haven't done anything. I'm innocent. It's a conspiracy by you know who,' apparently a reference to the British newspapers that tracked him down in Vietnam.

As Glitter serves out his sentence, the nightmare for Tran Thao, Tran Thu and their families continues.

'Gary is not a normal person. He is an animal and I hope he stays locked away for a long time,' Tran Thao said with bitterness. 'I know that he does not believe that what he has done is wrong.

'I am afraid because when he is free again, he will find another young girl like me and do those terrible things again.'