Thai Union Group, the Thailand-based seafood supplier, has confirmed it is the whistleblower in the US investigation into claims of price-fixing in the country's tuna sector.

In a statement to the Stock Exchange of Thailand today (11 September), Thai Union said its US subsidiary, Tri-Union Seafoods, had received a subpoena from the US Department of Justice requiring the business to provide what the Thai group said was "relevant information" in relation to the investigation.

However, Thai Union used the statement to the SET to confirm Tri-Union had received "conditional leniency" with respect to the investigation.

"Provided Tri-Union continues to fully cooperate with the DOJ, Tri-Union's conditional leniency status means that neither Tri-Union nor any cooperating executives or employees within the scope of the investigation will face criminal fines, jail time or prosecution," Thai Union said. "Thai Union was not involved in the conduct for which Tri-Union has received conditional leniency."

Allegations tuna suppliers in the US had fixed prices emerged in 2015. A lawyer for one of the plaintiffs suggested at the time "suspicious activity" could have emerged when the DOJ reviewed the potential impact on competition of Thai Union's move to buy rival US supplier Bumble Bee Foods, which was announced in late 2014. Thai Union called off the planned deal in December 2015.

Two Bumble Bee executives have pled guilty to conspiracy to fix the prices of packaged seafood sold in the country. In May this year, Bumble Bee itself submitted a guilty plea and agreed to pay a fine of US$25m. A month later, a former StarKist executive pled guilty to a charge of price-fixing.