THE Methodist Church has denied it ignored complaints about the former chairman of the Co-op Bank, the Revd Paul Flowers (above), who has been embroiled in a scandal after he was filmed allegedly buying drugs. Mr Flowers was arrested on Thursday by West Yorkshire Police as part of an investigation into "drugs supply", police said.

The exposé in the Mail on Sunday has led to a police investigation of Mr Flowers's alleged purchases of crystal meth, cocaine, ketamine, and of GHB. It has already led to the resignation this week of the chairman of the Cooperative Group, Len Wardle, who appointed Mr Flowers to the Bank in 2009. The Co-op is now holding a "root-and-branch" review of its structure.

On Wednesday, the Methodist Church announced that it had suspended Mr Flowers indefinitely. But the Church said that it would wait until the police investigation and any court proceedings had finished before conducting their own complaints process.

The Revd Gareth Powell, assistant secretary of the Methodist Conference, denied that the Church had been slow to pick up on complaints about Mr Flowers's behaviour.

He told Today on Radio 4 on Friday: "I don't think we were incurious. The difficulty about this tragic case is the extraordinary level of allegation and conjecture. It's very difficult to distinguish between those concerns based on hard evidence and those based on speculation. We cannot act on comments on a person's behaviour without any firm evidence."

Mr Powell confirmed that disciplinary proceedings had been opened after Mr Flowers had been convicted of gross indecency in a public toilet in 1981; but the Church had decided he could remain in his ministry. He admitted, however, the scandal had damaged the reputation of the Church and its clergy.

"Inevitably some of the speculation has raised questions, as it always does for the church, about the trustworthiness of ministers," he said. "It is regrettable when the allegations made against one minister tarnish the extremely good and honourable work undertaken by all of our ministers. The actions now under public scrutiny inevitably raise a question about the role of the Church."

In a statement, Mr Flowers, a minister for 30 years, said: "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 in 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."

He resigned the Co-operative Bank chairmanship in June. He had overseen the takeover of the Britannia Building Society, and a failed attempt to buy a number of Lloyds Bank branches. The moves left the Co-op with a capital shortfall of £1.5 billion, precipitating a rescue takeover which took the bank out of Co-op control. The Government has announced it will hold an inquiry into how Mr Flowers was deemed to be a suitable person to hold the chairmanship of a bank.

He is trustee on the Methodist Church body that manages its invested funds and property, and has worked with a number of charities.