The Department of Justice has extended its review of the AT&T proposal for its $39 billion dollar acquisition of T-Mobile due to requests for new information. This move could allow the Justice Department to extend it’s review of the proposed deal indefinitely.

Along with the request for more information, two unnamed sources said that antitrust authorities have sent “civil investigative demands” to competitors of the two carriers. These demands, which are best compared to a subpoena, inquire as to how the transaction would affect their business.

“This confirms that the government is going to do a deep dive into the transaction to understand what the implications are,” said Rebecca Arbogast, a Washington-based analyst with Stifel Nicolaus & Co.

While it is standard procedure under US antitrust law for regulators to issue second requests for more information, analysts alike agree that this deal poses a unique antitrust risk and regulators are carefully considering possible impacts of the deal passing.

T-Mobile and AT&T spokesman declined Bloomberg’s request for comment.

Bloomberg