The US Supreme Court appears sympathetic to a Florida fisherman who says the government went overboard in prosecuting him for throwing undersized grouper off his boat.

But the justices seemed to struggle over how to limit the reach of a law meant to tackle corporate fraud in the wake of the Enron accounting scandal - not to dole out punishment over a few missing fish.

The justices heard arguments in the case of John Yates, a fishing boat captain who claims he was wrongly convicted of destroying evidence - namely, the fish - that were under the legal minimum catch size.

Critics have derided the case as an example of government overreach. The Obama administration says the law prohibits destruction of "any tangible object" during a federal investigation.