Kim Kardashian's lawyer has challenged an imprisoned convict to take a lie detector test amid allegations he bedded the reality Tv star while she was engaged to basketball player Kris Humphries.

Andrey Hicks claims he is in possession of an email Kardashian allegedly sent him in 2011, when she acknowledged the alleged affair in Monaco and admitted it was "a mistake".

However, legal eagle Marty Singer is convinced the note is a fake and he has fired off a scathing letter to Hicks, who openly refers to himself a "greedy capitalist who went to jail for a greedy scheme".

In the message, obtained by editors at, Singer blasts Hicks as "a swindling convict and a liar" and encourages the prisoner to take a polygraph test.

Kardashian wed Humphries in August, 2011 after a whirlwind romance, but she moved to end the marriage just 72 days later. The divorce was granted last year (13), four months before she became engaged to rapper Kanye West. They exchanged vows in Italy in May (14).