The two sisters and an ex-girlfriend of gangland boss Willem Holleeder will testify in two major court cases, an Amsterdam court decided on Thursday.

Sonja and Astrid Holleeder and Sandra Klepper gave witness statements to the police about Holleeder’s involvement in gangland murders and will be called to testify in a major case concerning the liquidation of several gang members on November 30 and December 1, the court said.

Separate trial

They will also be called to testify against Holleeder in his separate trial on suspicion of involvement in the murder of underworld figures Kees Houtman and Thomas van der Bijl. This will take place between December and March, according to the Volkskrant.

Holleeder was jailed in the 1980s for kidnapping beer magnate Freddie Heineken and served five years in the early 2000s for his part in blackmailing three property tycoons.

The three women have described how Holleeder threatened to kill them and is a dangerous psychopath, according to the Telegraaf and NRC which reported on the witness statements last March.