Washington (CNN) -- The United States is concerned that Pakistan may have given China access to the helicopter that crashed in the U.S. raid on Osama bin Laden's compound, a U.S. official said Monday.
"We have reason to suspect China was given access but we cannot confirm it definitively," said a U.S. official who is not authorized to discuss intelligence matters publicly. "We have strong suspicions."
The comment came after news reports suggested Pakistani authorities may have allowed Chinese engineers to see the stealth aircraft.
A senior Pakistani intelligence official denied that ever happened. "This story is unsubstantiated and false," said the official, who asked not to be named because he is not authorized to speak to the media.
"Such stories are counterproductive when it comes to U.S.-Pakistani relations," the official added.
There was no answer Monday when CNN called the Chinese Embassy in Washington, and embassy officials did not immediately respond to an e-mail requesting comment.
The Financial Times newspaper in London reported that it had learned that "Pakistan allowed Chinese military engineers to photograph and take samples from the top-secret stealth helicopter." It added that "people close to the White House and the Central Intelligence Agency" told the paper that "the Chinese were in fact given access to the helicopter." China declined to comment, the article said.
The New York Times reported that "Pakistan's intelligence service probably allowed Chinese military engineers to examine the wreckage," citing "American officials and others familiar with the classified intelligence assessments." It noted that the "American assessments were disclosed" by The Financial Times.
When the aircraft crashed during the raid that killed the al Qaeda leader in May, Navy SEALs destroyed most of it to protect the technology. But the tail section remained mostly intact and it was that area that the Chinese engineers examined, according to the New York Times report.
Both newspapers pointed out that China and Pakistan enjoy a longstanding military relationship.
The raid at the beginning of May that killed bin Laden, staged without informing the Pakistani government, stoked tensions between the United States and Pakistan.
In July, the United States said it was withholding $800 million in aid to Pakistan.
"They've taken some steps that have given us reason to pause on some of the aid which we're giving to the military, and we're trying to work through that," White House Chief of Staff William Daley said at the time.