Justice minister Cathy Jamieson

The Scottish Nationalists have renewed their calls for the resignation of justice minister Cathy Jamieson following the mistaken release of another prisoner.

Jamieson has asked for a report, while the Scottish Prison Service said that a full inquiry is underway.

Private security firm Reliance has said it is largely responsible for the error, which led to the release of an inmate after his appearance at Motherwell District Court in connection with a fine.

The firm failed to realise that the prisoner should have been held to appear later on a separate charge at Hamilton Sheriff Court.

SNP justice spokeswoman Nicola Sturgeon described the situation as a "fiasco".

The latest incident comes just weeks after convicted murderer James McCormick was accidentally released after appearing before Hamilton Sheriff Court.

"Cathy Jamieson's position is now untenable. Responsibility for this fiasco lies at her door for two reasons," Sturgeon said.

"Firstly, she failed to ensure that the public were not put at risk when the contract was awarded to Reliance. She allowed the contract to be signed even though Reliance had 'underestimated' its task.

"And secondly, by refusing to suspend the contract when James McCormick was wrongly released, she took a gamble with public safety.

"That gamble has not paid off and, despite the assurances given to parliament by the minister two weeks ago, it is clear that Reliance is still not delivering an acceptable service."

She added: "If Cathy Jamieson can't see what now needs to be done, it is time she stepped aside and let someone who can do the job do it for her."

Conservative deputy justice spokeswoman Margaret Mitchell said that if it wasn't so serious the situation would be "a farce".

"Public confidence in our criminal justice system - and in the minister - is draining rapidly," she added.

"She [Jamieson] needs to get a grip to restore public confidence urgently."