A Christian human rights organisation is calling for the release of a pastor who disappeared three years ago in Malaysia. 

Pastor Raymond Koh has not been seen since he was abducted off the street near his home in Petaling Jaya on February 13, 2017. 

He went missing after being accused of trying to convert local Muslims, which is illegal in Malaysia. 

Malaysia's Human Rights Commission, the Suhakam, last year concluded that a special branch of the police was responsible for his kidnapping. 

A taskforce led by retired high court judge Abd Rahim Uda is investigating his disappearance but recently asked for more time to compile its final report. 

Release International, which campaigns for religious liberty, has launched a petition calling on the Malaysian government to secure the pastor's release.

The petition reads: "One of your country's loyal citizens has been missing for three years. Pastor Raymond Koh was kidnapped off the streets on February 13, 2017, and has not been seen since.

"His wife and children have been left to wonder what happened to him and whether he is still alive."

It adds: "We, Pastor Raymond's fellow Christians from around the world, call on your government to release any and all information related to the forced disappearance... including any involvement of Special Branch."

On Wednesday, it was revealed that Koh's wife, Susanna Liew, is suing the former inspector-generals of police Mohamad Fuzi Harun and Khalid Abu Bakar over her husband's disappearance. 

At a public forum in Kuala Lumpar last month, Liew said the family had been "frozen in grief" because of Koh's disappearance.

Speaking recently to Release's US partner organisation, Voice of the Martyrs, Liew said: "There was an eye witness, right smack in the middle of that scene.

"He thought it was a movie production. My children went door-to-door and found CCTV footage of the entire incident.

"It was a very military-style organisation, well-organised, and done in about 40 seconds. Last year, one of the officers confessed that the operation, the abduction, was done by the police.'

Release CEO Paul Robinson said that the perpetrators of Koh's abduction must be brought to justice.

"Three years to this day, Pastor Koh was abducted," he said. 

"Yet there has been no word whether Pastor Koh is dead or alive. Malaysia must secure his release and account for his disappearance, which by any standard is a crime."