Two governors cleared and no sackings over transfers of vulnerable prisoners in attempt to undermine inspections

Three prison middle managers have been given final written warnings and other disciplinary penalties for their role in the transfer of vulnerable prisoners in an attempt to undermine official inspections.

The results of an internal disciplinary inquiry were announced as evidence emerged that prisoners on the escape list – those who have escaped or are believed to pose a high escape risk – may have been moved out of certain London jails before security audits.

The Ministry of Justice said two governors at the two London prisons at the centre of the affair had been cleared of all charges, believed to include gross misconduct.

"Three members of staff have received disciplinary penalties. Charges were dismissed against two members of staff. No member of staff has been dismissed," said a ministry statement. The other disciplinary penalties include a block on future promotion for two years and the issuance of "advice and guidance" – in effect a caution.

It is believed the disciplinary hearings established that Ian Mulholland, who used to run Wandsworth prison, and Nick Leader, the former governor of Pentonville, were unaware of the unofficial swaps at the time they were going on. One is now head of custody for Wales and the other is running Whitemoor high-security prison, in Cambridgeshire.

A wider inquiry looking at the movement records of prisons across England and Wales is believed to have concluded that there is no evidence that the practice is widespread. However, it is understood that senior prison figures believe it is possible that certain jails in London have moved out escape-list inmates in advance of checks.

The extent to which this has gone on is difficult to prove as it is regarded as good practice to regularly move such prisoners between jails. This may mask any deliberate attempt to undermine a security audit.

The advantage to a governor of moving such prisoners would be that the inspectors would not need to check on the state of procedures for handling them. "It would be one less thing for them to worry about," said an insider.

• Prisons and probation