American Hall is trying to earn a spot in his fourth Olympic team
Olympic champion Gary Hall Jnr believes the recent dramatic increase in swimming world records has more to do with doping than hi-tech swimsuits.
Since the Speedo LZR Racer swimsuit was introduced this year, numerous world records have been broken.
"I don't have any proof but it's my gut feeling doping exists," said Hall.
"I am convinced there is an advantage to wearing the suits but I don't think it accounts for all the time drops we've seen."
Hall, the Olympic 50m freestyle champion who is trying to qualify for his fourth Olympics at this week's US trials, added. "I need to wait and see what it feels like to be shaved and tapered in these new technology suits.
"Do I think it (doping) is getting worse? Yes, I do. It's here, it's in the United States. I train with an international group of swimmers and all of them have stories and a few of them have had offers and I'm not at liberty to say (any more).
"Unfortunately, we rely on inadequate (anti) doping agencies for proof."
The 33-year-old also accused officials of not doing enough to rid the sport of performance-enhancing drugs.
"I have no idea where the sport is as a whole but to think it doesn't exist is foolish," he said. "It drives me crazy and I just don't know how to fight it.
"What bothers me most is the resignation and the attitude of the public that it is just part of sport today. We need to get over that because it is not ok."
Meanwhile, on the opening day of the trials in Omaha, Nebraska, six-time Olympic champion Michael Phelps and Katie Hoff set 400m individual world records.
Phelps broke his own world record of four minutes 06.22 seconds with a new mark of 4:05.22 seconds to secure his place in Beijing alongside runner-up Ryan Lochte.
Hoff beat Stephanie Rice's mark of 4:31.46 to qualify for Beijing in a time of 4:31.12 and will be joined by 15-year-old Elizabeth Beisel, who was well beaten in second.