One of the sisters of gangland boss Willem Holleeder has told a court she secretly recorded conversations with her brother because she feared his reign of terror ‘would never stop’ otherwise.

Astrid Holleeder said it was a ‘kamikaze act’ to tape the confidential discussions, in which Willem is alleged to have described his role in several underworld killings, and pass the information to the police. ‘If he’d discovered I was making recordings he would have killed me on the spot,’ she is quoted as saying by the Parool.

Her testimony, given to police earlier this year, implicates Willem Holleeder in the murder of six underworld figures. They include Cor van Hout, one of Holleeder’s accomplices in the kidnap of brewing magnate Freddy Heineken in 1983 and corrupt property magnate Willem Endstra.

Astrid Holleeder gave evidence in a heavily guarded courtroom at Schiphol airport, where judges are hearing an appeal case concerning several gangland killings known as the ‘Passage killings trial’. She, her sister Sonja and Willem Holleeder’s ex-girlfriend Sandra den Hartog are also giving evidence in Holleeder’s trial for the murder of former gang members Kees Houtman and Thomas van den Bijl.

Astrid Holleeder broke down as she gave evidence from a screened-off witness box, describing her brother as a psychopath with an ‘unhealthy blood lust’.

‘My brother doesn’t have friends, only potential victims,’ she said. ‘Any connection with him always ends badly.’

Anchor

She explained she was one of the few people Willem Holleeder took into his confidence. ‘He trusted me hugely, I was his anchor,’ she said.

At times she became visibly distressed and wept as she described the conflicting loyalties behind her decision. ‘He’s my brother, after all,’ she said. ‘And I’ve trapped him at his weakest moment. Betraying him like this is very hard.’

She volunteered her information to the police to guarantee her own safety, because her life would be at risk if he ever got out of prison.

‘Do you understand?’ she told the court. ‘To my brother it’s all one big game of chess. I’m just doing what I’ve learned from him.’