The Justice Ministry will begin research on how other countries employ satellite-based global positioning systems to locate people released from prison and to see if the systems work at discouraging repeat offenders.

Officials said they will not set the development of a similar system for Japan as the goal of the research, but said the move is likely to spark criticism among those who believe such surveillance violates human rights.

Countries including the United States, Britain, France, Germany and Canada already use GPS-based monitoring systems to track some former prisoners, and the ministry is planning to learn by the end of fiscal 2010, or March 31, 2011, why they did so, the purpose of their use, who is being targeted, what devices are used, and how the systems operate.

Some countries use GPS to prevent sex offenders visiting specific locations, while others use the technology to ease overcrowding in prisons by releasing offenders tagged with the devices.

The use of GPS was included as an item for study in an action plan finalized at a meeting of Cabinet ministers concerning crime prevention in December.