Ryan Koenigs, the leading sturgeon expert in Wisconsin, has been accused of accepting jars of caviar worth $20,000 in an illegal bartering scheme, The New York Times reports.

A group of state-employed biologists allegedly used sturgeon eggs intended for research purposes for personal gain and enjoyment instead – trading them with a caviar processor in return for caviar enjoyed at meetings.

Caviar from sturgeon eggs is worth nearly €30 a gram and is extremely popular on the black market.

Three people have been charged with bartering the eggs, while Mr Koenigs denies obstructing an investigation, misleading investigators and trying to conceal evidence.