The Sunday Times of London, citing unnamed sources, says Scotland Yard is investigating officers of the royalty protection service, who allegedly gambled millions of dollars over a six-year period and used police cars to courier tens of thousands of dollars in cash winnings.

Documents seen by The Sunday Times showed the officers' syndicate also lost more than $2.1 million in just one of the spread-betting firms that were employed in the gambling ring.

"It was a machine for churning out lots of money. It was mega money," an unnamed source told the newspaper. "Sometimes in my house I would have ($200,000) in cash laid out on the floor (ready to be handed out)."

The Times said the ring collapsed last year, leaving many officers with substantial losses. It said one has been criminally charged, but he reportedly claims he is being made a scapegoat.