OMAHA, Nebraska (AFP) - Swimmer Dara Torres, bidding to make a fifth Olympic team 24 years after winning gold in Los Angeles, knows success will be a cause for suspicion in some quarters as well as celebration.

Torres, 41 and the mother of a two-year-old daughter, will swim the 100m and 50m freestyles at the US Olympic swimming trials this week, vying to secure at the very least a relay spot and, if all goes well, an individual berth for the Beijing Games.

It's an attempt at yet another comeback in the wake of the one she pulled off in 2000, when she came out of retirement after seven years away from the sport and won two relay golds and three individual bronze medals in Sydney.

But in the wake of the BALCO steroid distribution scandal, which has caught Marion Jones - the 2000 Games athletics' golden girl - in its toils, Torres knows there will be some who question just what has fueled her comeback.

"Unfortunately, there have been athletes who have sat there in the past and looked everyone in the eyes and said 'I haven't cheated,'" she said.

"Now they're in jail or indicted or whatever," said Torres, a reference perhaps to Jones, who is serving a jail sentence for perjury after finally admitting doping, and baseball home run king Barry Bonds, who faces perjury charges over his claims never to have doped.

In this atmosphere, Torres said, "You are guilty until you are proven innocent. That's why I stepped up and asked to be tested. I could sit here and say I am not doping, but I have to prove it now."

Torres is part of a US Anti-Doping Agency programme involving about a dozen competitors who are making themselves available for numerous surprise blood and urine tests in a bid to help restore credibility to sport.

Torres said she had added incentive because she remembered the doping rumors that dogged her 2000 comeback.

"People said things about me in 2000, things were written about me and it was very hurtful and it was a big distraction," said Torres, who also competed in the 1984, 1988 and 1992 Olympics.

"I said, 'Look, I want to be an open book. I want people to know I'm doing this right. That I am 41 years old, and I'm doing this, and I'm clean.'

"I've swum against swimmers who were dirty my whole life, and it's just something I wouldn't do."

She said the programme was "a real pain."

"But I asked for this, and I want to prove I'm clean," she said.

"Now, if anyone questions me there's nothing else I can do. Anything they want to test, I have agreed to do.

"So if anyone accuses me of anything, I take it as a compliment. They must think I am going that fast, so I take it as a compliment."