The former chairman of NHS Croydon's audit committee has claimed the £22m financial black hole at the primary care trust could have been largely, if not entirely avoided.

John Power, a former director of finance at the Ministry of Defence, who chaired the audit committee between April 2007 and July 2008, was asked to comment on the overspend in 2010-11 accounts.

He gave evidence at a session of the South West London Joint Health and Overview and Scrutiny Committee on Monday.

He said: "I found some board members were unwilling to participate in the audit committee and got budget heads to speak instead. I was also met with a lack of enthusiasm when I established a tracker.

"The mispostings or non-postings of invoice or credit notes would not have been spotted from audit level. I can only imagine it was spotted by NHS staff, but there wasn't a mechanism for flagging this up."

Mr Power said he was brought in to replace the previous audit chairman, who was not qualified for the role after new Government guidelines were introduced.

He said some committee members were unhappy with his approach to the audit and complained behind his back, leading to his premature departure, before the overspend took place.

Speaking at the same session, South West London chief executive Ann Radmore, said NHS Croydon had ran up its £22m debt, because it was 'living beyond its means.'

During a presentation into the ongoing financial impact of the deficit, Ms Radmore said she was unable to say where the overspend was, but confirmed reserves from five other PCTs were used to fill the gap at NHS Croydon.