Oprah Winfrey is facing a $180 million lawsuit from a man previously accused of trying to extort money from the talk show host.

Keifer Bonvillain was accused of attempting to gain $1.5 million from the media mogul after he allegedly recorded phone conversations between himself and an employee of Winfrey in 2005. Bonvillain is said to have claimed the content of the recordings could have damaged the media mogul's reputation.

He allegedly emailed Winfrey in 2006 informing her of the recordings' existence and the "awful things" they contained - and requested the money to keep them quiet, or he would publish the content of the tapes.

Representatives for Winfrey and the FBI began working together in an attempt to catch Bonvillain and he was arrested in 2006 and charged a month later - although Bonvillain called the incident a "misunderstanding".

The charges were dropped in 2007 - on the condition that Bonvillain was monitored for a year, as well as undertaking 50 hours of community service, continual drug testing, forced to attend either school or work regularly and pay $3,000 to the FBI for the investigation.

But now Bonvillain is hitting back by claiming that his own reputation was damaged by the claims, and has filed a defamation lawsuit against Winfrey - seeking $180 million in damages.

His complaint states, "There was substantial damage done to my name and reputation on a world level. The extent of my damages is vast."

But a lawyer for Winfrey's company has dismissed the claims, insisting there was no wrongdoing on the chatshow host's part: "We know that this whole episode started when the plaintiff wiretapped a Harpo employee in California.

"We advised (the plaintiff) we believe that wiretapping was illegal, and this case will give us an opportunity to determine whether we were right about that."