Montgomery had his world record stripped over steroid abuse
Disgraced US sprinter Tim Montgomery has pleaded guilty to dealing heroin, just two months after being jailed for fraud and conspiracy offences.
The ex-100m world record holder and Olympic relay champion admitted to possessing more than 100 grammes of heroin with intent to distribute.
He faces a minimum five-year term for the drugs charges, and is due back in court for sentencing on 10 October.
Montgomery is already serving a 46-month term for a bogus cheque scam.
His lawyer, James Broccoletti, told the Associated Press that Montgomery has had time to reflect since he was jailed, and had decided to take responsibility for his actions.
"Tim is optimistic and he wants to proceed with life and get back on track," Mr Broccoletti said.
Montgomery, 33, was banned from athletics three years ago after he was found to have used steroids.
That ban also saw him stripped of his 100m world record.
Another former sprint champion, Marion Jones, Montgomery's former girlfriend, was implicated in the cheque fraud.
She was sentenced to six months in jail for misleading investigators over the fake cheques.