The November 17 group's main hitman, Dimitris Koufodinas, 61, was transferred from the maximum-security Korydallos prison near Athens to an agricultural prison near the central town of Volos. Such facilities are considered "open prisons," where inmates have greater freedom of movement within the grounds, which include fields and livestock units where they work.
The decision was strongly criticized by relatives of Koufodinas' victims, including conservative opposition leader Kyriakos Mitsotakis, whose brother-in-law was killed by November 17.
But Greece's left-led government defended the move, which followed a request from Koufodinas. The justice ministry said he was not getting preferential treatment.
"(Koufodinas) will continue to serve his sentence normally," a ministry statement said. "In any case, a large number of inmates serving life sentences are held in agricultural prisons and this has not created any problems so far."
Koufodinas, a beekeeper, has admitted to membership in November 17, Greece's deadliest terror group, which killed 23 Western diplomats and Greeks between 1975 and 2000. He was arrested in 2002 and given 11 life sentences.
In Korydallos, Koufodinas was held with other November 17 terrorists in a special underground wing with access to very few other prisoners.
The ministry said it was in the process of turning Korydallos into a prison for suspects in pre-trial detention, and wanted to transfer as many of its convicts as possible to agricultural prisons.
In June, the U.S. Embassy in Athens issued a statement deploring a 48-hour furlough granted to Koufodinas after he held a two-week hunger strike over the initial denial of his request.
Koufodinas will have the right to apply for early release in 2021, after he has served 19 years.
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