Consumer Reports says a Samsung phone that's advertised as being "water resistant" actually isn't.
The problem appears limited to the Galaxy S7 Active, a rugged model. The standard S7 and S7 Edge models have the same claims on water resistance and passed tests.
Consumer Reports, a non-profit organisation that is well respected for its product testing, said on Friday that it can't recommend the Active because it doesn't meet Samsung's own claims.
By contrast, Consumer Reports rates the S7 and S7 Edge phones as "Excellent" for their displays, battery life and cameras.
Maria Rerecich, Consumer Reports' director of electronics testing, said she was surprised the Active failed. She said Samsung's claims are usually "fairly good".
Samsung told Consumer Reports that it is investigating and has received very few complaints.
Samsung told The Associated Press that while the Active is meant to be one of the most rugged phones out there, "there may be an off-chance that a defective device is not as watertight as it should be".
Samsung says all S7 phones, including the Active, are designed to survive in up to 1.52 metres of water for 30 minutes.
Consumer Reports says that after a half-hour in water, the Active's screen flashed green and other colours and didn't respond to touch.
Tiny bubbles appeared on the camera lenses. Consumer Reports tested a second Active phone to verify results and it also failed.
Rerecich said it's likely that the problems affect only some of the units manufactured, but "we bought two and they both failed". Both units were bought online.
