Floyd Landis prepares for Stage Six of the Tour of Southland on November 4, 2010 in Invercargill, New Zealand. (Teaukura Moetaua/Getty Images)

By Marty Graham

SAN DIEGO, April 27 (Reuters) – Bicyclist Floyd Landis, stripped of his 2006 Tour de France win after testing positive for testosterone, is the subject of a federal investigation into a $450,000 defense fund he created and later abandoned, a legal source said on Friday.

A letter sent to Landis, 36, informing him of a grand jury probe indicated he was being investigated for mail and wire fraud linked to the Floyd Fairness Fund, said the source, who has seen the letter.

The fund, created in 2007, raised money to defend Landis from the allegations of using performance-enhancing drugs after the International Cycling Association stripped him of his title.

Phillip Halpern, a federal prosecutor in the San Diego U.S. Attorney’s Office, declined to comment on the investigation. Michael Henson, a New York publicist who was the fund’s executive director, did not return calls.

After a three-year battle, Landis did an about-face and admitted to doping, implicating teammates including bicycling legend Lance Armstrong, charges that Armstrong denies.

In 2010 he promised to refund the approximately $450,000 the Floyd Fairness Fund collected from individuals and supporters, but no refunds have been made, the source said.

Landis’s racing license with the U.S. Cycling Association expired in 2010 and has not been renewed, according to association officials. He now lives in Idyllwild, California.