The technology, installed at HMP Doncaster, allows staff to instantly see whether prisoners are attempting to smuggle in illegal contraband such as mobile phones, drugs and weapons.
The illegal items detected would have been destined for the prison wings, fuelling the illicit economy and potential violence.
John Hewitson, Serco Prison Director at HMP Doncaster, said: "The introduction of this new technology is having a very positive impact on our ability to intercept illegal contraband.
"We take a zero-tolerance approach to people attempting to smuggle things like phones and drugs into the prison and we work closely with the police to prosecute anyone we find doing so.”
The prisons chosen have been identified at most of risk of smuggling.
Prisons Minister, Alex Chalk MP, said: "The new technology is having a hugely positive impact, stemming the flow of contraband into jails and allowing staff to focus on rehabilitation.
"The scanners form part of our wider aim to transform prisons, stepping up security to cut crime and ultimately better protecting the public."
The equipment was funded by the Government’s £2.75 billion commitment to transform the prison estate. This includes £100 million to bolster prison security, clamping down on the weapons, drugs and mobile phones that fuel violence, self-harm and crime behind bars; £2.5 billion to provide 10,000 additional prison places and create modern, efficient jails that rehabilitate offenders, reduce re-offending and keep the public safe; and £156 million to tackle the most pressing maintenance issues to create safe and decent conditions for offender rehabilitation.