Amir Khan's former trainer Oliver Harrison says he is mystified by the Commonwealth lightweight champion's decision to dump him on the brink of a world title shot.

Harrison, who has been in Khan's corner for all 17 of his professional contests to date, said he had not spoken to the fighter since his last win over Martin Kristjansen at the Bolton Arena on April 5.

Khan is set to announce on Thursday that he has teamed up with a leading American trainer - possibly former world champion Buddy McGirt.

But Harrison told the Bolton Evening News: "We were just around the corner from a world title, which we would have won.