An investigation is under way after a man died soon after downing dozens of live bugs and worms in an eating contest in South Florida.

Edward Archbold collapsed outside the Ben Siegel Reptile Store in Deerfield Beach moments after winning the competition.

The 32-year-old was rushed to hospital but was pronounced dead there. Authorities are awaiting the results of an autopsy.

It remains a mystery because none of the other competitors became ill.

The bugs were taken from a batch which, according to Siegel's attorney, was "safely and domestically raised in a controlled environment as food for reptiles."