His jailing comes after the prosecution decided not to appeal against his 18-month prison sentence for leaking papal documents.

Gabriele had been under house arrest since he was found guilty on October 6 of stealing documents from Pope Benedict XIV's apartments. A judicial source said later he would not be appealing against the verdict.

"Given that no appeals have been lodged against the sentence of October 6 in respect of Mr Paolo Gabriele, it becomes definitive,", a statement from Father Federico Lombardi, the director of the Holy See press office, said.

"As a result, on the warrant of the president of the court the prosecutor gave orders this morning for his imprisonment, in carrying out the sentence," the statement said.

"The warrant should be executed during the day."

The former butler was found guilty of leaking hundreds of sensitive Vatican documents in a case that has been dubbed "Vatileaks" and included allegations by a former governor of the city state of massive fraud within its walls.

A papal pardon has not been ruled out.