The head of the Dutch National Crime Squad has told the ABC he was shattered when he first discovered the former assistant director of the NSW Crime Commission was conspiring with traffickers linked to a Dutch drug syndicate.
Dutch police had worked with Mark Standen at the NSW Crime Commission and also with Australian Federal Police investigating Dutch drug syndicates trafficking to Australia.
On ABC Four Corners tonight, Commissioner Jan Boersma says it was "shattering news" when he was told Standen had been caught up in a conspiracy with one of the Amsterdam drug syndicates.
Dutch police originally tipped off the AFP that a key figure in the Dutch syndicate was in business with Sydney food wholesaler Bill Jalalaty.
Jalalaty turned out to be a close friend of Standen.
Commissioner Boersma says he was fearful the investigation into Standen would leak.
He says Dutch police decided they would only ever refer to Standen by the code name "Rupert".
A Sydney jury last week found Standen guilty of conspiring to import and supply 300 kilograms of pseudoephedrine and perverting the course of justice.
Prior to his conviction, Standen was the most influential drug investigator in NSW, thanks to his senior position at the secretive NSW Crime Commission.
The organisation is charged with targeting organised crime and drug trafficking.
Hundreds of intercepted phone calls, meetings and emails put into evidence in Standen's trial are examined in tonight's Four Corners program.
They reveal a far-reaching conspiracy from Amsterdam to Dubai, Bangkok and Sydney.
Standen's conviction has rocked police agencies around Australia and the world.
Four Corners has been told by law enforcement sources that further investigations are now underway into other allegations of corruption involving Standen and his relationship with criminal informants.
Standen spent 30 years as a criminal investigator in the former Narcotics Bureau, the federal police, the National Crime Authority and the NSW Crime Commission.
NSW Police Minister Mike Gallacher told Four Corners accountability and governance issues at the NSW Crime Commission had been ignored for too long.
Last week he ordered a special commission of inquiry to address these.
But Mr Gallacher also expressed concern that there was what he called, "a turf war" between the NSW Crime Commission and its watchdog, the Police Integrity Commission, which is investigating allegations of misconduct against other crime commission officers.
Four Corners airs tonight on ABC1 at 8:30pm