Three prisoners have won the right to challenge policy decisions of their governor which, they claim, led to innocent inmates suffering harsher conditions than guilty ones.

David Gorman, sentenced in 1998 to 18 years' imprisonment for rape, and Darren Vickers, convicted in 1999 of the murder of eight-year-old Jamie Lavis, have always protested their innocence, as has the third prisoner, who does not wish to be named.

Last week, Mr Justice Moses granted the inmates, who are all at Frankland prison, in Durham, a judicial review of the governor's decisions. The hearing is expected to be in October or November.

The central issue is the incentives and earned privileges scheme, the aim of which is to reward prisoners for good behaviour. Prisoners can then enjoy "enhanced" rather than "standard" status.

In order to qualify for the IEP scheme, prisoners at Frankland must first "address their offending behaviour and undertake courses such as the sex offenders' treatment programme (SOTP)".

However, some prisoners say that they are the victims of a catch-22 situation: a prerequisite for admission to a SOTP course is an admission of guilt; prisoners who maintain their innocence cannot undertake the courses and consequently are not eligible for privileges.

According to regulations, inmates who maintain their innocence should not be treated adversely, yet in practice this is what happens.

Also, privilege levels are supposed to be "portable" between one prison and another. Both Gorman and Vickers were on "enhanced" status at previous jails, but upon arrival at Frankland were downgraded to "standard" - as a result, they believe, of their refusal to admit guilt.

In consequence, they had fewer privileges - they were, for example, allowed less frequent contact with family and friends.

"What is happening at Frankland is a form of torture," said Gorman. "Inmates who maintain their innocence have to live alongside the murderer who has better living conditions, gets more family visits and spends less time locked up in his cell."

David Wilson, a former prison governor who is now professor of criminal justice at the University of Central England in Birmingham, said: "What this judicial decision must do is to make the prison service look closely at the domination of prison regimes by psychologists who demand prisoners acknowledge guilt before they go on these programmes.

"If they don't, prisoners not only have fewer privileges but are unlikely to get parole - a fact that has been consistently denied by the prison service."

See also:
Guardian special report: Prisons