Paralympic Swimming Legend -- Disqualified Over Olympic Rings Tattoo

A world record setting paralympic swimmer has been DISQUALIFIED from a race at the IPC European Championships ... all because he didn't cover up a tattoo of the Olympic rings on his chest.

The swimmer is British legend Josef Craig -- who set the world record for the 400m freestyle at the 2012 Summer Paralympics.

19-year-old Craig -- who has cerebral palsy -- was competing at the 100m freestyle at the IPC race in Portugal on Sunday (and WON his heat) ... but was disqualified immediately following the race.

A spokesman for the event said the Olympic rings tat violated a "body advertising" ban -- "the athlete did not wear a cover and was therefore disqualified."