X-ray scanners are due to be installed in 16 of the country's "most challenging" jails, including the one in Wandsworth.

The "cutting edge" scanners, specially developed for the Prison Service, can produce "instant images from inside the human body" and reveal internally concealed contraband like drugs, phones and weapons, in a level of detail not previously available, according to the Ministry of Justice (MoJ).

Prisons with high volumes of remand prisoners, which the MoJ said pose the "greatest risk of smuggling", are being prioritised.

Earlier this month an inspection report found violence had "markedly increased" at HMP Winchester, which has been the subject of a prison documentary, and more than half of the prisoners said it was easy to get drugs into the building.

A week later the watchdog found there had been dramatic improvements at HMP Liverpool, previously criticised as having some of the worst conditions ever seen by inspectors, but there were "still too many drugs entering the prison".

In June a review of standards at HMP Birmingham questioned an "inexplicable" failure to secure funding for scanners to prevent drugs being smuggled into the jail.

Installation will begin in the spring with all scanners anticipated to be in place by the summer.

Around £28 million, out of a £100 million fund to boost security in prisons, will be used to pay for all the scanners which are eventually hoped to be installed in the majority of closed adult male jails.

The contract for providing them has been awarded to company Adani Limited.

It follows the successful use of older models of similar scanners in the 10 Prisons Project to crack down on violence and drug use in Hull, Humber, Isis, Leeds, Lindholme, Moorland, Wealstun, Nottingham, Ranby, and Wormwood Scrubs prisons.

Prisons Minister Lucy Frazer said: "New technology is a vital part of our efforts to stop those determined to wreak havoc in our jails.

"These scanners will help to stem the flow of contraband into jails and allow officers to focus on rehabilitation."