A family rivalry over property was behind the assassination of former Pakistan Minority Affairs Minister Shahbaz Bhatti, who was gunned down earlier this year, and the killing was not religiously motivated, a media report said on Tuesday.

Bhatti's murder in Islamabad was due to a property dispute between relatives and police investigators have concluded the killing was not religiously motivated in their latest report despite the fact that the Punjabi Taliban had claimed responsibility for the assassination, The Express Tribune newspaper reported.

However, Bhatti's murderers have fled Pakistan and are currently believed to be in Dubai or Kuala Lumpur, according to an investigator. The murderers have not been identified as yet.

"We will approach Interpol for their arrest," an investigator said. "Shahbaz's murder is said to be linked to a chronic rivalry with relatives who lived in Faisalabad five years ago," claimed an investigator associated with the joint investigation team that probed the assassination.

Interpol has not been contacted for assistance because there are no clues about the exact location of the accused, said an unnamed Interior Ministry official.

"We cannot put our case before Interpol without substantive proof," he said.

"Firstly, we wanted to close the investigation but then we learnt that there was a chronic ethnic and property dispute between the two families which led to Shahbaz's murder," said an unnamed police official.

New clues have led police to a family who left Pakistan due to the rivalry with the Bhattis, the JIT said in its latest report.