Haq's widow Sufia Begum told The Daily Star about an anonymous phone call her sister-in-law received two days ago. "You people have to pay for filing the case against Kajal. Don't you have other school-going children in the family?" she quoted the caller as saying.

"I'm feeling very insecure. On the one hand, Kajal is still on the loose and on the other, these phone threats keep coming. I have four school- and college-going children," Sufia Begum said.

She expressed her willingness to meet the prime minister to apprise her of the family's predicament and also to seek her help in getting back the property her husband bought from Kajal.

Haq paid Tk 30 lakh to Kajal about two and a half months ago as per an agreement in connection with the purchase of SH Mansion, an eight-storey building in Sadarghat, but Kajal never handed the building's ownership over to him.

The Jubodal leader went into hiding after remains of Haq and his son Russell Sheikh were found in 200 pieces two days after their disappearance on March 26. Haq's driver Moazzem was earlier found hacked to death on the outskirts of Dhaka.

Investigators said a manhunt is on to arrest Kajal and different places in the capital and other districts are being raided. They said police are also looking for seven to eight of his close associates.

"Investigation has revealed that these men could be linked to the murders," said Abul Khair, investigating officer (IO) of the case.

Police confirmed that Kajal, also accused in the murder of Sergeant Farhad on Jagannath University College campus, made at least three calls to Shamsul Haq's mobile phone before the businessman and his son left home with Tk 2 lakh.

Earlier on Sunday, Guddu alias Shamim Alam, arrested in connection with the murders, was placed on a fresh three-day remand after expiry of an earlier five-day remand.

IO Abul Khair said Guddu has disclosed some important information.