Former two division world champion Amir Khan has defended his hire of controversial fitness coach Victor Conte. Conte was jailed in 2005 after pleading guilty to conspiracy to distribute banned steroids. His association with Khan has been criticized by the UK Anti-Doping organization.

Khan, who fights Mexico's Julio Diaz on Saturday night, said Conte, who was introduced to the boxer by trainer Virgil Hunter, had passed on a lot of invaluable tips.

"The advice he's been giving me has been brilliant," Khan told the BBC's website. "I know he's had a bad background and has done things he shouldn't have.

"Virgil Hunter is my trainer and he's the one who's told me we are going to use Victor Conte as an assistant in a way, as he has a team of trainers who can teach you stuff.

"On the training methods … he's brought so much good training into the game. He's introduced me to a lot of new trainers who have helped me on my running, sprinting, on my engine really, which is working my fitness, also breathing methods and telling me what to do and what not to do."

Conte was at the center of the BALCO doping programme that included several high-profile athletes, including Marion Jones and Tim Montgomery.

A steroid specifically designed to fool testers, tetrahydrogestrinone (THG), was produced and distributed by BALCO.

After his release from prison, Conte became an anti-drug campaigner who works with several anti-doping bodies in a bid to clean up sport.