Kim denies being involved with NFL player

Kim Kardashian's attorney fired a letter to In Touch Weekly on Monday, saying the magazine falsely claimed the reality TV star had been involved with New England Patriots player Bret Lockett while she was dating her fiance, New Jersey Nets player Kris Humphries.

"Can you believe these rumors!!?!" Kardashian 30, tweeted Wednesday. "I'm setting the record straight!"

She told E! News Wednesday that the magazine's claim "is absolutely not true," adding "I have no idea who this person [Lockett] is."

Lockett himself, however, told the web show "TMZ Live" that he has proof the two had been intimate while Kardashian was dating Humphries, saying he could present phone records, text messages and revealing cellphone pictures as evidence in court.

Kardashian's legal letter, from attorney Dennis A. Roach to In Touch's entertainment director, Rachel Biermann, stated the magazine's alleged source, model-actress Lauren London, a friend of Kardashian, was the victim of impersonation.

"I have spoken to Jenifer Levin, counsel to Lauren London, who has indicated that a third party is impersonating Lauren London," Roach wrote. "Consequently, any information that you receive directly or indirectly through this [person] should not be relied upon."

The letter demanded the magazine cease publication of the issue or face unspecified legal repercussions.