The Federal Bureau of Investigation said on Tuesday it had opened an investigation into potential insider trading in shares of H.J. Heinz Co just before a takeover announcement last week.

The announcement follows the U.S. Securities and Exchange Commission's decision to freeze assets connected to a Swiss trading account from which the alleged insider trades were made.

"The FBI is aware of the trading anomalies the day before Heinz' announcement," a spokesman said. "The FBI is consulting with the SEC to determine if a crime was committed."

Heinz on Thursday announced a deal to be acquired for $23 billion by Warren Buffett's Berkshire Hathaway Inc and Brazil's 3G Capital.

(Reporting By Emily Flitter; Editing by Gary Hill)