By ROB DRAPER and STEVE LANDELLS - More by this author »
Last updated at 20:18pm on 12th January 2008

Disgraced sprinter Dwain Chambers is poised for a dramatic comeback after secretly returning to training and showing form that suggests he could be selected for Britain in the World Indoor Championships in Valencia in March.

If he is picked, it would cause governing body UK Athletics major embarrassment as the sport desperately tries to retain its credibility and shake off the taint of the BALCO scandal that exposed Chambers as a drug cheat and saw Marion Jones jailed for six months on Friday for lying to investigators in the United States.