GAZA CITY, Gaza Strip — A Palestinian human rights group released new details Monday about a Gazan man who vanished on a Ukrainian train and resurfaced in an Israeli prison, saying that he was dragged out of his sleeper car, hooded and handcuffed by Israeli agents, forced onto a plane and taken to Israel.

It was the most detailed account of how Dirar Abu Sisi, a top engineer at Gaza’s power plant, made his way to Israel after disappearing Feb. 19 en route from Kharkov to Kiev. Israeli authorities have said little about the case because of a gag order.

The Gaza-based Palestinian Center for Human Rights said it was permitted to send a lawyer to visit Abu Sisi, a 42-year-old father of six, on Sunday.

Abu Sisi, who is married to a Ukrainian, was in the country while applying for residency. He said at least six people who identified themselves as Mossad, or Israeli intelligence, interrogated him before flying him to Israel.

His Ukrainian wife accused Mossad of abducting him to sabotage the power plant, but denied speculation that he was tied to Hamas militants. Abu Sisi is a top official at Gaza’s electric plant, meaning he would need to have good relations with the Hamas government.