Britain's Queen Elizabeth II narrowly escaped disaster in 1970 when a large wooden log was placed on a railroad track in an apparent attempt to derail her train as she traveled across Australia, a retired detective said Wednesday.

Former New South Wales state Detective Superintendent Cliff McHardy, 81, said the Queen and her husband, Prince Philip, were traveling through the Blue Mountains on April 29, 1970, when their train struck the log, which became stuck under the front wheels.

But the locomotive was not moving fast enough to become derailed, sliding about 200 yards (meters) before coming to a stop, said McHardy, who investigated the incident at the time.

McHardy said markings at the scene suggested the log had been deliberately rolled onto the tracks. A security train that swept the tracks an hour before the Queen's locomotive chugged through the area spotted nothing, he said.

McHardy's claims were first reported in his local paper, the Lithgow Mercury, on Jan. 22. He has since repeated the story to several other media outlets, including Australia's Macquarie Radio on Wednesday. He did not immediately return messages from The Associated Press.

A spokeswoman for the New South Wales police said officials were looking into McHardy's story to determine its validity.

McHardy said police investigating the incident were ordered to keep details quiet to avoid embarrassing Australia.

The retired detective, who was in charge of the Lithgow police force for 11 years and now lives in the Blue Mountains town of Glenbrook, about 90 miles (145 kilometers) northwest of Sydney, said he was finally speaking out in an attempt to crack the case.

"It was one of the big regrets of my police service," he told the Mercury. "We never came up with any decent suspects because if we interviewed people we seemed to be talking in riddles. We couldn't disclose what our inquiries were about."

A Buckingham Palace official said Wednesday that the royal family's staff were unaware of the incident and did not intend to comment.

McHardy told Australian Broadcasting Corp. radio that he had previously divulged the facts to the former editor of the Lithgow newspaper, Bill Leighton, but asked him to not to publish the story. Leighton has since died.

Len Ashworth, who has edited the newspaper for the past 25 years, said he had long known the story and decided recently that it was time to publish.