A SERIAL killer should be quizzed over the murder of a Westcliff cafe owner 44 years ago, her son believes.

Fears have been raised Patrick Mackay may be released after it is believed he was moved to an open prison.

However questions remain about several killings he confessed to but was never put on trial for.

Ivy Davies, 48, was battered to death with a metal bar at her home in Holland Road in February 1975.

Mackay, a violent alcoholic who was diagnosed as a psychopath at the age of 15, was questioned at the time.

He has killed at least three people by forcing his way into their homes, where he would strangle, stab or beat his victims around the head.

But at least eight other murder probes where he was a suspect remain unsolved, after he agreed to admit to three counts of manslaughter by diminished responsibility at a pre-trial hearing the same year.

The claims have emerged in a new book by former Echo crime reporter, John Lucas, who has investigated Mackay and his alleged crimes.

Ivy’s son, Vic Davies, said: “I have asked for Mackay to be interviewed again and I’ve also asked if I could meet him myself with officers present.

“But I’ve been told that it wouldn’t be possible. It’s been so long since he was spoken to, with everything that’s been uncovered it’s time to ask him again.”

His plea comes amid fears that Mackay could soon be moved to an open prison and ultimately released.

In 1975 when it emerged that he had been placed in mental hospitals, prisons or special schools 19 times before the age of 22.

Mackay later admitted that he knew of Ivy Davies and had considered robbing her. Mackay was allegedly heard bragging about her murder while on remand in Brixton Prison, but when he was driven to view her cafe and nearby home, he could not pick them out. He later flatly denied having anything to do with her death. Two men were questioned at the time, and another man, from Basildon, was arrested and questioned over Ivy’s murder in 2005.