Rolph, who won the 100 individual medley on Saturday and also took two silvers, swam the 200 medley in 2min 10.60sec, which matched the time set by the East German Petra Schneider in Gainesville, Florida, in January 1982.
When Schneider swam there were no official European records for the short- course events and the East German's mark officially ranks as a "standard time" which must be bettered for a record to be recognised.
It was a bitter blow for Rolph, who said: "I couldn't believe it when I turned round and saw the time. I though it must be wrong."
Had she set a European record, Rolph would have won pounds 2,000. Instead she was given a leather coat that was awarded by the sponsors for the best performance by a woman swimmer in the championships.
"I'm not bothered about the money I just want my name to go down in the book," she said.
Britain's Mark Foster also took his second gold of the championships by winning the 50m freestyle in 22.25sec. Foster, winner of yesterday's 50m butterfly, qualified only third in the morning's heats but his time of 22.25sec in the final put him 0.26sec ahead of Italy's Rene Gusperti.