The Federal Railroad Administration, the nation’s railroad agency, has brought in the Boring Company, the tunneling firm founded by Elon Musk, to help with a multibillion-dollar Amtrak project, according to three people familiar with the discussions.

Federal Railroad Administration officials have talked with employees at the Boring Company about assessing the costs and progress of the Frederick Douglass Tunnel program, a new tunnel along a busy Amtrak stretch connecting Baltimore to Washington and Virginia. Amtrak initially expected the development to cost $6 billion, but now estimates it could cost as much as $8.5 billion.

As part of the talks, officials with the Department of Transportation, which oversees the Federal Railroad Administration, met with employees from the Boring Company last month and were told that the firm could find ways to build the tunnel more cheaply and efficiently, according to two of the people familiar with the discussions.

A Transportation Department spokesman, Nathaniel Sizemore, confirmed that the Boring Company was one of several firms being consulted for the purposes of awarding a new engineering contract. He declined to name the other companies.

The talks have raised concerns about Mr. Musk’s conflicts of interests as he juggles his businesses, along with his role as a top adviser to President Trump. Mr. Musk leads or owns at least six companies, including the electric automaker Tesla and the rocket company SpaceX. At the same time, he has overseen the so-called Department of Government Efficiency, which has slashed jobs and resources at federal agencies that regulate his businesses.

Mr. Musk has overseen the so-called Department of Government Efficiency, which has slashed jobs and resources at federal agencies that regulate his businesses.Credit…Haiyun Jiang for The New York Times