Cop: Travolta Suspect Flushed Evidence

A Bahamas cop just testified defendant Pleasant Bridgewater admitted to giving key evidence in the case the dead goldfish treatment ... flushing it down a toilet at her home on the island.

Det. Sgt. Debra Thompson testified today about what went down on January 22 when they arrested Bridgewater -- who allegedly helped broker the extortion deal between paramedic Tarino Lightbourne and John's lawyer.

Thompson said the day of the arrest, they searched Bridgewater's office at her law firm ... with Bridgewater in tow.

At the office, Thompson said Bridgewater told them they weren't going to find what they were looking for -- a copy of the extortion document -- because she burned it with a candle and then flushed it down one of the toilets at her house.

Thompson said they then escorted Bridgewater to her home, where she actually showed them the candle in question -- so they took photos of it.

Thompson didn't say if they also took pics of the commode.