Government agencies in the U.S. and Europe are investigating the pricing of electronic books, officials confirmed this week.

At a congressional hearing today, Sharis Pozen, acting antitrust chief for the U.S. Department of Justice, confirmed that it is investigating possible collusion in the pricing of e-books. “We are investigating the electronic book industry, along with the European Commission and the states attorneys general,” she said, referring to investigations in Texas and Connecticut.

She didn’t specifically mention Apple, No. 3 in the Internet Retailer Top 500 Guide, but did say the department is collaborating with the European Union. The European Commission is the executive body of the European Union.

The commission announced this week its own antitrust investigation, and specifically said it was looking at Apple, along with the following major book publishers: Hachette Livre, Harper Collins, Simon & Schuster, Penguin and Verlagsgruppe Georg von Holzbrinck, which owns Macmillan. The commission wants to know “whether these publishing groups and Apple have engaged in illegal agreements or practices that would have the object or the effect of restricting competition,” according to a commission statement this week.

Apple offered no immediate comment, nor did most of the publishers named in the antitrust investigation. A spokeswoman for Harper Collins would say only that the company “is cooperating with these investigations.”