Justice Minister Antonis Roupakiotis is reportedly planning the introduction of tougher restrictions on the issuing of furloughs and conditional release periods to prisoners, particularly those who have violated the terms of leave granted to them in the past, as well as the use of an electronic monitoring system -- widely used in the US and elsewhere in Europe -- involving ankle bracelets.

The minister is said to be mulling the introduction of the tagging system -- which has been widely condemned by human rights groups but which is in force in many countries including Britain, France, Italy, Sweden, Portugal, Belgium and Cyprus -- following several cases of Greek prisoners violating the terms of their furloughs.

One of the most high-profile cases is that of Michalis Makriyiannis, the 49-year-old convict serving four life sentences for five murders who disappeared last month after being granted a brief period of leave. Another case was the disappearance in July of Nikos Maziotis and Panayiota Roupa, two alleged leading members of the Revolutionary Struggle guerrilla organization. The pair were released from prison on strict conditions after serving 18 months in pretrial custody and remain at large.

Although the percentage of prisoners who disappear while on conditional leave or furlough is quite low -- standing at just 3.6 percent -- the majority of cases involve convicts serving life sentences or pretrial detainees deemed to be dangerous such as the aforementioned terror group suspects.

According to the current Greek law, a convict serving a life term must carry out at least eight years of his sentence before being entitled to apply for leave. If the crime was drug-related, they must wait 10 years before they can apply. In either case, the punishment offenders face if caught while violating the terms of their release is negligible -- a few additional months in prison -- and is not believed to act as a deterrent.

A new tougher legislative framework -- foreseeing stricter conditions for the approval of applications for leave and the introduction of an electronic bracelet for prisoners -- is expected to be announced by Roupakiotis in the coming days.