The Star newspaper said the athlete was being sued for child negligence by a former girlfriend with whom he allegedly fathered a now two-year-old son, and that the estranged couple were involved in a fight in a Nairobi hotel on Saturday.
It said the woman had confronted Kemboi over a lack of child support, and that the star tried to force the woman to again have sex with him, prompting a fight and the intervention of hotel security.
Kemboi angrily dismissed the allegations, saying he was a victim of extortion.
“That lady is a frustrated person. We were friends some time back but she is now a married woman. How can I be involved with somebody else’s wife?” the 31-year-old told AFP by telephone from his hometown of Eldoret.
“I did not have a child with her. She should have gone to court to sue me for the alleged paternity instead of tarnishing my name in the media,” he added.
Kemboi, who is also a police officer, beat a similar case in 2012 when another woman claimed he stabbed her after she refused his sexual advances but later decided to drop the charges.
The athlete, who had denied all the charges, was bailed in time to participate in the London Olympics, where he won the 3,000m steeplechase gold medal, becoming the first Kenyan to take two Olympic titles in the event, which he also won in Athens in 2004.
He is also a three-time world champion.