Murderer Jeremy Bamber has launched High Court legal action over a refusal by the prison service to downgrade him from maximum security.

East Anglian Daily Times: White House Farm Tolleshunt D'Arcy, near Maldon, Essex Picture: ARCHANTWhite House Farm Tolleshunt D'Arcy, near Maldon, Essex Picture: ARCHANT

The 59-year-old is serving a full-life tariff after being convicted of murdering his adoptive parents, sister and nephews at White House Farm, Essex, in August 1985.

Bamber has always maintained his innocence and the challenge is the latest in a long-running battle to clear his name.

He claims his sister, Sheila ‘Bambi’ Caffell, who suffered from schizophrenia, killed parents Nevill and June and her twin six-year-old boys Nicholas and Daniel before turning the gun on herself in a murder/suicide.

Bamber is now seeking a legal challenge at the High Court over a decision taken in March by the director of the long-term and high security estate - part of the prisons and probation service - not to downgrade him from a Category A prisoner, or to direct that an oral hearing on the issue take place.

East Anglian Daily Times: Bamber's latest legal bid is the latest in a string of challenges to clear his name Picture: PABamber's latest legal bid is the latest in a string of challenges to clear his name Picture: PA (Image: PA Wire/PA Images)

Category A prisoners are considered the most dangerous to the public and held in maximum security conditions.

MORE: Murderer Jeremy Bamber: New White House Farm ITV drama is ‘a disgrace’At a remote hearing on Monday, lawyers for Bamber asked Mr Justice Julian Knowles to grant permission for a full hearing of Bamber’s challenge, arguing that the decision was “unreasonable”.

In written documents before the court, Bamber’s barrister Matthew Stanbury said his client, who is being held at HMP Wakefield in Yorkshire “is a model prisoner”.

Mr Stanbury said an independent psychologist’s report, commissioned by Bamber’s solicitors, concluded he had met the test for downgrading a Category A prisoner and that these conditions were “no longer necessary” for managing him.

He argued that the decision not to downgrade Bamber from Category A was “unreasonable” as it “substantially misrepresented” the opinion given by the independent psychologist.

He also said that “fairness required an oral hearing” over whether Bamber should be downgraded, for reasons including the fact that he “has served 35 years without ever having an oral hearing, and the passage of time means that a risk assessment is more difficult without a face-to-face assessment”.

The Ministry of Justice is opposing Bamber’s action.

He had an appeal against his convictions dismissed by the Court of Appeal in 2002, and also had a High Court challenge to the Criminal Cases Review Commission’s (CCRC) refusal to refer his case for another appeal rejected in 2012.

Bamber is in the process of pursuing a fresh application to the CCRC.

Mr Justice Julian Knowles reserved his ruling to a later date.

MORE: Notorious killer who murdered five family members hopes phone evidence could clear himAn ITV television series dramatising the murders aired in January this year, and was criticised by Bamber.

He labelled White House Farm “a disgrace” - but ITV highlighted the “meticulous research” which went into making the drama.