Charities are preventing people with criminal records from volunteering, even though their offences often have no relevance to the roles they are applying for.
This is one of the findings revealed in Involving Ex-offenders in Volunteering, a new guide by Nacro and Volunteering England.
Mervyn Barrett, one of the guide's authors, said: "We know of many people who have been turned down for voluntary work, often on the basis of old and wholly irrelevant convictions."
The guide reveals that although 25 per cent of the working population have been convicted of criminal offences, only 7.5 per cent of volunteering applicants have criminal records.
It concludes from this that about two-thirds of potential recruits with criminal records are avoiding applying for roles where disclosures are required. "A lot of people call Nacro's helpline because they are reluctant to disclose their criminal records, fearing they will be discriminated against - with good reason," said Barrett.
He believes that part of the problem is that Criminal Records Bureau disclosures offer no interpretation of an individual's past.
"The disclosures simply list their offences, but of course there are always circumstances that contribute to a person's actions," he said.
Another contributing factor is a pervading climate of fear. "Charities are also risk-averse when they should be risk-aware," Barrett added.
"If there's a one in 1,000 chance that someone could re-offend, volunteer managers would rather not take that risk in case it's their jobs that end up on the line," he said.
The guide, funded by the Volunteering Hub, calls on charities to re-examine their disclosure practices.
"Charities should not ask for disclosures unless it's necessary for the role," said Barrett.
"Where they do ask, they need to be more sensitive. Unless charities change, many people will continue to be put off volunteering. Not only are ex-offenders missing the chance to turn their lives around, but communities are also losing out."
Individuals who have not re-offended in the past two years are usually no more likely to offend again than those without records, according to Nacro.
The report argues that Criminal Records Bureau disclosure alone is not effective in identifying people who could pose a risk.
Nacro receives 15,000 calls a year about disclosures.