Mossad agent Ben Zygier stripped a sheet from his prison cot and, with the aid of a stool, hanged himself from the bars in his cell bathroom, despite earlier reports indicating that no means of suicide were found near his body, according to a newspaper report of leaked findings from the Israel Prison Service’s investigation of his 2010 death.

Zygier, who was not on the Ayalon Prison’s suicide watch, took the sheet to the bathroom presumably on the pretense to wash it, and tied it to the bars on his window without guards noticing, the preliminary investigation found. Because Zygier was not deemed at risk of suicide, the guards only checked in on him once every 20 to 25 minutes, rather than every few minutes, according to the findings published in Maariv Tuesday.

From the bathroom, which was not monitored by security cameras, a 20-minute window was more than enough time for Zygier to end his life, the paper reported.

The Mossad agent was imprisoned by Israeli authorities after he reportedly revealed information to officers from Australia’s ASIO internal intelligence agency, including on a major upcoming operation in Italy, according Australia’s ABC television.

Former Australian foreign minister Alexander Downer told ABC on Tuesday, however, that passing secrets to ASIO was likely not the reason he was jailed.

“I suspect it was something more serious than just sharing information with ASIO,” he said.

Zygier, known as “Prisoner X” until last week, was secretly arrested in 2010 and hanged himself several months later, despite being held in the ultra-secure cell with 24-hour surveillance.

The leak from the Prison Service investigation published Tuesday conflicted with an earlier report on Israel’s Channel 2 which said that Zygier was under constant surveillance and was considered a suicide risk. The earlier report, which cited unnamed members of the rescue crew called to the prison, also said that nothing that could have been used to commit suicide was found near his body.

The findings of the Prison Service investigation of Zygier’s death reportedly contributed to the decision by Rishon Lezion Magistrates’ Court Judge Dafna Baltman Kadrai that his death was a suicide.

The Prison Service noted in recent days that there is no way to prevent a prisoner from committing suicide unless prison psychiatrists rule him to be a suicide risk. Had Zygier been deemed such, he would have been imprisoned in the “spaceship,” a special cell with foam walls and without ledges, furniture or bars with which a prisoner can kill himself. In extreme cases, the wardens can strap a prisoner on suicide watch to the bed.

“It’s an extreme step that’s taken only after actual threat,” the Prison Service told Maariv. “It’s not like in Zygier’s case. The wardens received instructions not to speak with the prisoner except with regards to food and daily inspections.”

The Israeli defense lawyer who met with Zygier in jail two days before his suicide on December 15, 2010, said last week that Zygier was “absolutely not” suicidal. But lawyer Avigdor Feldman also noted that Zygier had been held for eight or nine months in solitary confinement in a cell designed for Israel’s most dangerous criminals, and that this could play havoc with a prisoner’s psyche.