David Plunkett

At 1.30 am on Sunday they received a call from his friend saying the pair had lost each other and she reassured the friend that she would call David on his mobile Mrs Plunkett said: "We rang and when David answered he was incoherent, there was no noise in the background and it struck me he was on his own. Ten minutes into the phone call he started screaming. He was howling and yelling, it was horrendous." She handed the phone to her husband Mike and dialled the emergency services but little could be done because they did not know where he was. They managed to keep the phone line open until 4.30am but there was no further contact.

Records from his mobile phone have shown that when he took the call from his parents he was between Salford Quays and the Old Trafford football ground. After the recovery of his body from the canal a police spokesman said: "A post mortem examination has been carried out and further tests are required to ascertain the cause of death." The Daily Star Sunday can reveal tragic David Plunkett’s chilling screams, heard by a 999 call handler, were not taped because the recorder was not working.

The officer who dealt with the “distressing” call was so appalled by the blunder she later resigned. And the family of Souvik Pal said families were not getting proper answers from the police. Detectives last week hit out at an expert’s claims that a killer dubbed “The Pusher” is on the loose after we revealed dozens of bodies have been found in Manchester’s canals. Another death last week took the toll to 62 since 2008. Greater Manchester Police said they were concerned “families struggling to come to terms with what happened will have had their anguish and pain resurrected again”. But the families hit back, saying they want answers from the police.

The phone call from David, 21, who came from Halifax, W Yorks, was the last anyone heard from him before he was found dead in the Manchester Ship Canal three weeks later. He vanished after leaving a nightclub at Trafford Park near Manchester in April 2004.

His inquest heard that his anguished parents rang him to check if he was OK after hearing he had lost his pals. He started to scream and howl, they said. They dialled 999 on another phone and held the two handsets together so the police operator could hear his distress. It was the last time they spoke to their son. The Daily Star Sunday has seen an email sent to Birmingham City University’s Professor Craig Jackson after he told our investigator a serial killer could “not be ruled out”.