They were the 6.7 seconds that plunged athletics into a moral quagmire and left Dwain Chambers talking of becoming an Olympic athlete and a totem for the anti-drugs crusade. “If you want to catch a thief, hire a thief,” the disgraced sprinter said after his controversial comeback. “I want to put back into the sport what I've taken away. I'm not a bad guy.”

Chambers, who completed a two-year ban for taking tetrahydrogestrinone (THG) in 2006, has forced a legal battle with UK Athletics (UKA) after gaining the qualifying time for the World Indoor Championships trials in Sheffield this weekend. Niels de Vos, the UKA chief executive, does not want Chambers there as the sport tries to salvage the last vestiges of credibility, but has a porous legal case.

Chambers believes that he is being made a scapegoat for the sport's ills and can point to the presence in Sheffield of Carl Myerscough, a shot putter, who has served a drugs ban, as evidence of double standards. But rather than attack UKA, Chambers says he wants to work with De Vos.

“The best person to show young athletes what not to do is me,” he said after comfortably gaining the 6.9sec qualifying time in his 60 metres heat at the Birmingham Games at the National Indoor Arena on Saturday. “I went and took drugs, it gave me huge success financially, but look at the repercussions. I was mad at the world for a long time and thought it was everyone else's fault, but you grow up. I've tried fighting and that didn't work. Now I want to be part of the solution, I want to be used as a positive example of what you should and shouldn't do.

“There's no better way ahead than to get together [with De Vos] and shake hands. I want to run, he wants to make the sport look good and maybe we can meet in the middle.”

De Vos has made a public stand against Chambers's return. However, his remark that Chambers needed to be on the doping register for 12 months before his comeback was undermined by the IAAF, the sport's world governing body, which confirmed last week that he had never officially retired. “I never came off the register,” Chambers, who was tested three weeks ago, said. “It was UKA's decision. Unfortunately, that's left us both in a sticky situation.”

The idea that Chambers could work with UKA will be anathema to De Vos, who has called for the criminalisation of doping. It is likely that Chambers will run at the trials, whereupon UKA will seek loopholes in its selection criteria if he wins the 60 metres to gain what would normally be an automatic place in the Great Britain team. The bad news for De Vos is that Chambers's time in Saturday's final was an impressive 6.6, good enough to break his meeting record and defeat the promising Harry Aikines-Aryeetey. “I'm in good shape to do well at the World Indoors,” Chambers said.

Chambers, recalled to the Britain team in 2006, before the appointment of De Vos, admitted that he is “running for free” because he has to pay back his winnings. He also claimed that he could improve the sport. “I want to be forgiven,” the 29-year-old said. “Everyone makes mistakes and I want to go out and help the sport because it's going through a rough time. I don't want to be part of the rough, I want to be part of the smooth.”

He has been training alone since October and said that he may also try to overturn the British Olympic Association's life ban automatically imposed on drug cheats. “The Olympics are the pinncale of any athlete's career,” he said. “I may be the first to challenge the ban legally.”

De Vos's desire to stiffen UKA's resolve against drug cheats is laudable, given the damage done to the sport by the likes of Chambers, Marion Jones and Justin Gatlin. However, Myerscough's situation and the employment of Linford Christie as a UKA coach, despite having served a two-year drugs ban while semi-retired, were noted by Chambers's lawyer.

“I'm in love with track,” Chambers said. “I was watching Rocky Balboa and it's about how many punches you can take and still get up. I'm here to help.” UKA will beg to differ as it consults its lawyers today for the knockout blow.