File photo of United Launch Alliance launching an Atlas V rocket with an United States Air Force OTV-4 onboard from Cape Canaveral Air Force Station, Florida, May 20, 2015. REUTERS/Michael Brown

WASHINGTON (Reuters) - The Pentagon said on Friday its inspector general will investigate comments made by a former executive with United Launch Alliance (ULA) who suggested the department had improperly tipped a competition for rocket launches in its favor.

Defense Secretary Ash Carter has referred the matter to the Pentagon’s independent watchdog, on the recommendation of chief arms buyer Frank Kendall and Air Force Secretary Deborah James, Pentagon spokesman Peter Cook said.

“The Secretary is concerned by recent statements regarding competition for national security space launch,” Cook said.

John McCain, chairman of the U.S. Senate Armed Services Committee, on Thursday urged Carter to investigate what he called troubling remarks by Brett Tobey, who resigned Wednesday as vice president of engineering for ULA. The firm, a joint venture of Lockheed Martin Corp and Boeing Co, has been the sole provider for U.S. military launches for nearly a decade.

Tobey said during a lecture at Colorado university on Wednesday that the Defense Department “bent over backwards to lean the field” to ULA’s advantage in a competition with new market entrant Space Exploration Technologies, or SpaceX, owned by billionaire Elon Musk.

Tobey also said the Pentagon was trying to figure out “how do we silence McCain,” who has urged the government to penalize ULA for failing to bid in the competition despite receiving $800 million in government funding for launch services every year, on top of its actual launch contracts.

ULA has said Tobey’s comments were “inaccurate.” The sole provider for U.S. military launches for nearly a decade, ULA is scrambling to restructure so it can compete with SpaceX.