A prisoner who threatened a pregnant woman in a 'frightening' burglary was caught in his cell with an axe strapped to his stomach, a court has heard.

John Charlton was serving an 81 month sentence at HMP Wayland when a contractor realised three of his tools had gone missing.

Norwich Crown Court heard on Monday a tool box had been left by an open window by the exercise yard around midday on January 30 of this year.

The prison wing was put on "lockdown" as officers searched cells looking for the missing items.

"It is not possible to say it was the defendant who took them from the tool box, but by the time a search was conducted he had taped the axe to his stomach, secreted underneath his clothing," said Andrew Oliver, prosecuting.

Charlton, 39, claimed he had bought the axe for "two vape capsules" with the intention of using it to slice meat in the prison kitchen.

"It is not a completely attractive explanation," said Andrew Thompson, mitigating.

"He had a responsible job working in the servery. From time to time joints of meat would become available and he would take on the role of preparing them and cooking them.

"He had used various methods to improvise, including the top of a tin can. When it became apparent someone was offering for sale a cutting implement he purchased the item."

Charlton claims he was told he would not be prosecuted if the axe was dropped in the "amnesty bin", but before he could do so he was searched by security guards.

But he admitted possession of a bladed article at an earlier hearing at magistrates court.

"Inmates were told if whoever had them put them in the amnesty bin there would be no further action," Mr Thompson said.

"He proposed to do that and taped it to himself so he could go to the amnesty bin and drop it in.

"He was given some assurances that when he was released from his cell and put the items in the bin that would be the end of it."

The court heard Charlton's previous convictions include an aggravated burglary in Lowestoft in January 2016.

"The defendant was with two others and knocked on the door of a flat in Lowestoft," said Mr Oliver.

"The lady who answered it was heavily pregnant and was punched in the stomach. They concealed their identity by wearing face masks and it was described as a frightening experience.

"They were said to be holding knives or similar items."

Judge Katharine Moore adjourned sentencing until September 26 to gather more information from the prison.

"On the face of it this is so serious you face immediate custody," she told Charlton.