The troubled Babyshambles rocker - who vowed to stay clean after completing six weeks in rehab recently - is now considering returning to rehab after being filmed injecting heroin at his Wiltshire home on Friday.
A spokesman for Pete's record company EMI said yesterday : "Peter Doherty would like to apologise to the medical staff, fans and well-wishers who have helped and encouraged his progress in fighting his addiction to heroin.
"His ongoing rehabilitation was a source of such pride to him that Peter and those closest to him thought that he was close to winning his personal battle with the drug. However, Peter sadly relapsed last week and is now looking to check himself back into a rehab clinic so that he can try to continue the hitherto excellent attempts he had made to break free of heroin.
"He realises that he has not only let himself down but has let down those who trusted and encouraged his efforts and he is filled with remorse for what he describes yesterday as 'a stupid, stupid action for which I feel only shame.' "
It is not known if Pete's rehab plans will affect his upcoming Babyshambles tour which kicks-off at Manchester's MEN Arena on November 22.
Pete's relapse comes just weeks after a magistrate released him from the six months left on his two-year drug treatment order after he tested negative for crack cocaine and heroin.
He was arrested last December while carrying heroin, crack cocaine, cannabis resin and cannabis. He was arrested again in January while in possession of heroin, crack cocaine and cannabis.
Less than two weeks ago Pete was given a four-month suspended sentence and a 12-month drug rehabilitation order in relation to his May arrest for driving illegally while in possession of drugs in West London.