A man who committed "appalling and horrific" murders is fighting for the legal right to remain anonymous while he seeks rehabilitation.
The convicted double killer is asking for his identity not to be revealed as he challenges a decision refusing him unescorted leave in the community, which is a key step to eventually being set free by the Parole Board.
In what is believed to be the first case of its kind, the man, who can only be referred to as "X", is appealing against High Court judge Mr Justice Cranston's order that he can be named.
Stephen Knafler QC, for X, argued in the Court of Appeal that X, who sexually mutilated one of his victims, had a legal right to anonymity because he is now a hospital patient being treated for mental illness - and that trumps the public interest in knowing his identity.
Mr Knafler said there was a strong public interest in mental patients who had committed crimes receiving protection from publicity "no matter how horrific those crimes are - and I accept that these crimes are high up on the scale of horrific crimes".
The top human rights QC told three appeal judges the fact that X "carried out particularly violent and notorious offences" was no reason to deny him the anonymity every mental health patient is entitled to when their cases are considered by courts and mental health tribunals.
The legal challenge is being heard by Lord Dyson, Master of the Rolls, sitting with Lord Justice Maurice Kay and Lord Justice Floyd.
They have reserved their judgment to a later date.
The anonymity issue arose because X came to London's High Court earlier this year to challenge a 2013 refusal by the National Offender Management Service (Noms) to grant him unescorted community leave.
The decision was upheld by the Justice Secretary on review in December 2013 on the grounds that X currently posed an unacceptable risk for unescorted leave.
X's lawyers argued before Mr Justice Cranston the refusal was unreasonable and interfered with his rehabilitation.
A journalist covering the case challenged X's identity being kept secret. The judge observed the judicial review hearing had been held in the public domain and said he could see no reason for anonymity.
But he delayed giving judgment on X's legal challenge to give the appeal court time to consider the anonymity issue.
The court heard that X was convicted almost two decades ago of two murders in which both his victims received multiple stab wounds and one was sexually mutilated.
He has served the minimum period he had to remain in custody, and the authorities can now consider whether it is safe to release him on licence.
While in prison he was diagnosed with a personality disorder and other mental health problems and transferred to Broadmoor high security hospital under the 1983 Mental Health Act.
Since then he has been moved to a medium secure hospital where, the court heard, he has progressed to having frequent unescorted leave within the hospital grounds - and over 300 escorted leaves in the community.
Putting the case for anonymity, Mr Knafler told the appeal court: "There is absolutely no precedent for the order Mr Justice Cranston made in this case. I cannot find a single case where it has been done before."
X's case had "crossed the line" and he had become entitled to anonymity once he became a Broadmoor patient.
Allowing X to be identified by the media could lead to him becoming the victim of public hostility if he was spotted in the community, said Mr Knafler.
Naming him might also interfere more generally with his rehabilitation and deter other mental patients from coming to court to seek justice over their treatment.
Mr Knafler said there was a long-standing common law approach that all mental health patients would have their personal details kept confidential by first tier and upper tier mental health tribunals considering their cases, and fairness demanded that principle should also apply to X in the High Court and the Court of Appeal.
He said the 1913 case of Scott v Scott, which dealt with what should be made public in cases concerning children and adults lacking mental capacity, supported his argument.
The Domestic Violence Crime and Victims Act 2004 also supported it as the the Act required only limited information about offenders to be provided to victims of sexual and violent offences.
Lord Dyson said X's offences were "appalling", adding: "We are in a situation here where there is a particular public interest in dealing with somebody who has murdered people."
But Mr Knafler said: "The primary duty in cases involving mental patients is the care of the mental patient.
"The broad principle of open justice will yield to the primary duty owed to the patient. It is not an absolute duty, but it is sufficiently important to outweigh the open justice principle.
"The concern is that the mental patient would suffer intrusion from the media, and probably worse from the public." "
Kate Olley, appearing for the Justice Secretary, Chris Grayling, said he was "strongly opposed to the idea there should be any general presumption of anonymity" in cases like that of X.
Mr Grayling remained "neutral" with regard to X, but believed every case should be considered on its own merits and in the light of its own circumstances, which could vary widely, said Ms Olley.