Lord Dear, who once led West Midlands Police, is joined by Labour MP Frank Field and Judge Alan Pardoe QC in a letter calling for a proper investigation.
They claim the Church did not interview key people before branding Bishop Bell a sex abuser.
In October 2015 the Church of England released a statement apologising to a woman who claimed she was abused by the respected Bishop Bell in the late 1940s and early 1950s.
It also paid compensation to the woman, who cannot be named for legal reasons.
Sussex Police has revealed it would have arrested Bishop Bell and interviewed him on suspicion of serious sexual offences had he still been alive.
A Church spokesperson said the decision to accept Bishop Bell was a paedophile was "not taken lightly or without consideration of the impact on the reputation of George Bell".
The group supporting Bishop Bell has written to the Archbishop of Canterbury Justin Welby asking him to apologise to Bishop Bell's family and launch an investigation.
Frank Field MP, a former member of the Church of England General Synod, told the Sunday Telegraph: "There has been a grave miscarriage of justice here. The church acted in secrecy. We don't know what the charges were, who were the authorities which made the judgment and how that judgment was arrived at.
"If this could happen to a man like Bishop Bell it could happen to someone who is unknown and does not have influential friends to fight for them. We need a much more robust system for dealing with this kind of allegation."
A Church of England spokesperson said: "The decision to settle the civil claim relating to the activities of Bishop Bell and make a formal apology was not taken lightly or without consideration of the impact on the reputation of George Bell.
"However in this case, as in others, the overriding goal was to search out the truth and issues of reputation cannot take priority over that.
"Any suggestion that the reputation of the Church, or its ministers, should take precedence over the search for the truth is fundamentally misplaced."