LONDON (AP) -- London police said Tuesday they have arrested a man on suspicion of fraud after he allegedly duped an American woman into handing over tens of thousands of dollars for an investment related to the upcoming Olympics.

The online scam involved an alleged contract to supply buses for police officers for the games, police said.

The fraudster, 24, first contacted the 69-year-old woman on an online dating website. Police said that once he befriended her, he tricked her into handing over 140,000 pounds ($220,000) as an "initial" investment into the business.

Police say they were worried about fraudsters using the prestige of London's Metropolitan Police department to secure the trust of victims.

"Suspect anyone you don't know personally who is asking for money in this way and who use the name of a well-known organisation, such as ours, in an attempt to add credence to their claims. It is almost certainly not genuine," Detective Superintendent Nick Downing said.

No other details about the victim were revealed.

Police arrested a man and a woman for suspected involvement in the same scam in December. Both were bailed pending further questioning.

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