A prominent Pakistani journalist investigating the alleged murder of a British woman in an "honour killing" says he has received death threats. Samia Shahid, 28, from Bradford, was strangled to death while visiting her family in northern Punjab last month. Her husband, Mukhtar Syed Kazam, said he believed his wife was killed because her family disapproved of their marriage. Shahid's first husband, Mohammad Shakeel, her father, Mohammad, and another cousin who are suspected of her murder are all on the run, according to Pakistani police. It is alleged that Shahid, 28, had been tricked into travelling to Pakistan in July and killed for divorcing her first husband and remarrying against the wishes of her family. The stories you need to read, in one handy email Read more The case, which has been highlighted by the Bradford West MP Naz Shah, has become a priority for Pakistan after the country's interior minister, Chaudhry Nisar Ali Khan, announced that he had ordered a rapid investigation. The Guardian has learned that a journalist in Pakistan, who has been investigating Shahid's death, has made a formal complaint to police after allegedly receiving death threats from a British man. Raja Waqar said he received five disturbing phone calls in which he was told he would be killed and his children would also be harmed if he continued to pursue information about Shahid's murder. During the phone calls, the longest of which is said to have lasted eight minutes, Waqar said he was told: "If you carry on doing this I'm going to kill you and your children." Waqar, who works for the AAJ TV station in Karachi, says he began receiving calls from a British mobile phone number on 24 July. The calls, from a man who only identified himself as Ali, continued for two days and became increasingly disturbing, he said. Speaking from Pakistan, Waqar said: "When I started covering this story I started receiving threats from a man called Ali. He was ringing on an English mobile number. "He asked me why I was covering the story and I told him that as a journalist in the area for the past 15 years, it was my duty to cover the story and that I had smelled that this was not a natural death. "He told me to drop the story and when I refused he said he was going to kill me and my children." Waqar was told by his bureau chief at the TV station to contact the police and filed a complaint in writing. He said: "This was my assignment and I was not going to allow him to threaten me. But after he kept calling and telling me to stop I had to call the police. He told me to leave it because Samia was not my sister but it was very clear to me that she had been murdered- I have no doubt about it." A West Yorkshire police spokesman said: "We are aware of a report of a Pakistan-based journalist who has allegedly been receiving threats. They have reported this matter to the Pakistani police." He added: "West Yorkshire police is currently reviewing all previous contact with Samia Shahid, including any alleged criminal offences and the action taken as a result. Her death remains a matter for the Pakistani authorities and we are continuing to liaise with them and with the Foreign and Commonwealth Office." Shahid returned to Bradford from Dubai, where she had been living with Kazam, her second husband, last September to try to build bridges with her family. She asked a female police officer to chaperone her to the family home in Manningham, Bradford, after allegedly being harassed by one of her relatives who wanted her to return to her first marriage. West Yorkshire police confirmed that a man received a harassment warning following the meeting but the force declined to identify the offender. Shahid's friends in Bradford said the beauty therapist was not frightened for her life but was increasingly stressed about what some relatives were telling her mother and father. "I could tell from her Snapchats that she was really affected by her relatives saying stuff to her family, her parents," one friend said. "She was saying "People can't keep their nose out of things'." She added: "She wasn't a scared person. It would take a lot for her to fear stuff. She felt, "Why are they doing stuff like that?' but I don't think she was scared because she is a strong person in her character. "She was just stressed for her family - she didn't want her parents to be stressed out because of what her relatives were doing. That was her main concern[rather] than being scared for herself." Shahid's family in Bradford claimed she had died from natural causes on 20 July and police initially said there were no visible injuries on her body. However, police last week launched a murder investigation after a forensic examination found she had died from asphyxiation.