The former chairman of the Co-op Bank, Paul Flowers, is 'seeking help' after a video emerged showing him handing over money to buy hard drugs.
Flowers, who is also a Methodist minister, claims that job pressures and a family tragedy led him to buy crack cocaine, crystal meth and ketamine.
The 63-year-old ex-bank chief, who oversaw the Co-op's near collapse, was filmed counting out £300 in cash. The Mail on Sunday said a friend of Flowers, Stuart Davies, handed over the footage and a series of text messages.
One of the texts said: "Have 2 bags of Charlie here and have ordered another 5... enough? Px".
Davies said he was "disgusted by the hypocrisy" of a man who chaired the anti-drugs charity Lifeline and had written newspaper articles about the perils of drug use, according to the Mail on Sunday.
Methodist minister Flowers was paid £132,000 a year as chairman of the Co-op Bank from 2010 until May 2013, when he stepped down.
Flowers said he resigned as chairman to take responsibility for a £1.5bn capital shortfall.
The former Co-operative Bank chairman gave testimony to the Treasury select committee over the bank's £700m losses. Flowers blamed the stress of his job for his drug taking. A text from him said: "I was 'grilled' by the Treasury select committee yesterday and afterwards came to Manchester to get wasted with friends."
Flowers apologised for his behaviour, saying: "This year has been incredibly difficult with a death in the family and the pressures of my role with the Co-operative Bank.
"At the lowest point of this terrible period I did things that were stupid and wrong.
"I am sorry for this and I am seeking professional help and apologise to all I have hurt or failed by my actions."
The Co-op Bank refused to comment on the claims because they were of a personal nature, while the Methodist Church have suspended Flowers and is carrying out its own investigation, saying: "We expect high standards of our ministers."