"We're aware of the trading anomalies the day before the announcement," Federal Bureau of Investigation spokeswoman Kelly Langmesser said on Tusday.
"And we're consulting with the SEC to see if a crime was committed."
The Securities and Exchange Commission said on Friday ihat it had identified highly suspicious Heinz trades made one day before Berkshire Hathaway and 3G Capital announced they were acquiring the condiment giant in a $28 billion deal.
The SEC said that it had obtained an emergency order to freeze a Swiss bank account suspected of use in the trades.
It said unknown traders earned $1.7 million in profits through the "irregular and highly suspicious" trades booked on Wednesday.
The SEC said it believed the traders had knowledge of the takeover ahead of the announcement early Thursday morning in New York.
Langmesser declined to say if the FBI has opened a criminal investigation into the case.