The Corrections Department is asking the police to explain why it told its officers Rimutaka Prison is at maximum capacity.

In an email sent by a senior sergeant, leaked to the Herald, Wellington police officers were told repeat bail and warrant offenders may be held in police custody for prolonged periods due to the prison being almost full.

The Herald reports the arrangement would be in place until further notice.

Katie Scotcher asked Corrections' national commissioner Leigh Marsh if Rimutaka prison was at maximum capacity.