The Church of England has said an inquiry into allegations made against former deputy London mayor Ray Lewis would bring a resolution to the matter.
Mr Lewis resigned on Friday amid allegations of inappropriate behaviour and financial irregularities.
Mayor Boris Johnson said as Mr Lewis was now not in public office an inquiry would be a waste of taxpayers money.
But Reverend Chris Newlands, who works in the diocese where Mr Lewis served as a vicar, said answers were needed.
Mr Newlands, chaplain and spokesman for the Bishop of Chelmsford, said an inquiry would have offered a resolution.
"There have been a lot of very serious and important questions raised in the last week and the inquiry...would have been a very good way of clearing the air and making it possible to discover the truth about some of these issues," he said.
"When something so fundamental has been questioned I think it does need some time spent to ensure that proper answers are given to the questions that have been raised."
Mr Johnson's office has said it was "inappropriate" for taxpayers to fund an inquiry into a private individual who had already resigned.
Ray Lewis used to head up the Mayor's youth policy
Mr Lewis has been feted by the Conservative Party leadership as helping with answers to youth crime and party leader David Cameron insisted appointing him was a good idea.
He said: "You have to take some risks in politics, if you all do is just appoint stiff-suited career politicians, who've been very careful not to put a foot wrong, you end up with a bunch of stiff-suited politicians who've never put a foot wrong - but you might not bring in the creativity.''
The allegations against Mr Lewis date back to his time as a vicar in the Parish of St Matthew in West Ham, east London, in the late 1990s.
They include claims he received money from a man with learning difficulties and owed a debt to a fellow priest.
In another case, a female parishioner went to church authorities and the police after giving Mr Lewis £25,000 to invest for her.
She started receiving regular interest payments but these allegedly stopped after a few months.
Mr Lewis stepped down after it emerged the mayor had been told wrongly that he was a serving justice of the peace.
Mr Lewis's resignation follows that last month of Mr Johnson's Deputy Chief of Staff James McGrath.
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