Robot guards with sensors to detect abnormal behaviour will soon begin patrolling South Korean prisons to ease the burden on their human counterparts, researchers said Thursday.

A group of scientists has developed the robot warders under a one billion won ($850,000) project organised by the Ministry of Knowledge Economy.

The robots -- 1.5 metres (five feet) high and running on four wheels -- will mostly be used at night.

They can connect prisoners with officers through a remote conversation function, according to a statement from the Asian Forum for Corrections (AFC), a South Korea-based group of researchers in criminality and prison policies.

It pioneered the project with the justice ministry's cooperation.

The robots' sensors will enable them to detect abnormalities such as suicidal behaviour and violence and report it to officers in charge, the statement said.

Professor Lee Baik-Chul of Kyonggi University, who led the design process and heads the AFC, said it was intended to let human guards focus more on correction and rehabilitation efforts.

"As we're almost done with creating its key operating system, we are now working on refining its details to make it look more friendly to inmates," Lee was quoted by Yonhap news agency as saying.

Three robots will be tested at a correctional facility in the southeastern city of Pohang next March when development is completed.

South Korea aims to be a world leader in robotics. It has already designed models to teach English in schools, stand guard on the border with North Korea, fight taekwondo bouts, act in plays and clean a home.