A Palestinian who went missing last month in Ukraine after boarding a train in Kharko headed to Kiev, was kidnapped by agents of Mossad, the Israeli spy agency and brought to Israel against his will, according to a report published Monday by the Gaza-based Palestinian Center for Human Rights.

The report says one of its lawyers was able to visit Derar abu Sisi, 42, in his Israeli prison cell, and learn the truth behind the Gaza resident's sudden disappearance.

Abu Sisi, who is director of operations at the Gaza power generation plant, told the human rights group that he was travelling to Kiev on Feb. 19 to meet with his brother, who was coming from the Netherlands. Three persons, two in military uniforms, entered his cabin on the train and asked for his passport. Abu Sisi refused, but they threatened him and forcefully took his passport. They then handcuffed and hooded him and took him off the train as it stopped in Poltava.

He was then taken by car to Kiev where he was held in an apartment. Six people, who introduced themselves as Mossad agents, immediately began to question him. He was later put on a plane, which landed at an unknown place after about four to five hours. Approximately 30 minutes later, they took off again and the flight lasted for approximately one hour and upon landing Abu Sisi found himself in Israel.

Abu Sisi, who is married to a Ukrainian woman and has six children, was denied contact with a lawyer for 25 days during which he was heavily interrogated.

Israel justified the abduction by claiming that Abu Sisi is a member of the Islamist Hamas movement, which controls the Gaza Strip, and that he has good relations with top Hamas leaders, suggesting he may have information useful for Israeli intelligence.

The Palestinian Center for Human Rights accused the Ukrainian government of colluding with Israel in the kidnapping. It said that Abu Sisi was not legally arrested by Ukrainian authorities and he was not brought before any court.

It expressed concern over his health and the psychological impact of the kidnapping on him and his family, calling for his immediate release.