There may be "some merit" in three-strikes legislation for repeat offenders, says Prime Minister John Key.

The man who held a US girl captive for 18 years is now under investigation for a string of unsolved murders.

Convicted murderer George Baker has released a fellow prisoner who he took hostage yesterday.

George Baker (above left) murdered Liam Ashley (above right) in the back of a prison van three years ago. Police and prison officials are now trying to prevent another tragedy, after Baker took a hostage at Auckland Prison this afternoon.

Prison containers are for shifting goods, not housing people, says a leading penal reform advocate after today's announcement the units will be trialled at Rimutaka Prison from next March.

199 people were searched at a combined Department of Corrections and police checkpoint at Auckland Prison at Paremoremo on Saturday.

The man who negotiated the return of one of the stolen war medals says he should not spend any time in jail if convicted of methamphetamine charges.