A British Airways pilot who killed his wife with a claw hammer will not have his bid for parole heard in public because it would breach his human rights.

The parole board rejected calls for a public hearing by the family and friends of his wife, Joanna Simpson, 46, who was bludgeoned to death by Robert Brown in Ascot, Berks, in October 2010.

They were backed in their demands by the Justice Secretary, who argued that “increased transparency was vital to building public confidence in the parole system”.

Campaigners supporting Ms Simpson’s family include Carrie Johnson, the wife of the former prime minister, Sir Robert Buckland, former justice secretary, and Baroness Newlove, the victims’ commissioner for England and Wales.

They have claimed Brown should have been convicted of murder because of the level of planning that went into the killing.

He was acquitted of murder after successfully pleading diminished responsibility by reason of a disorder brought on by a number of stresses.

He was set to be freed in November last year after serving half of his 26-year jail sentence but Alex Chalk, the justice secretary at the time, intervened to refer the case to the parole board under public protection powers.

Ruling on the application for a public hearing on Thursday, Sir John Saunders, chairman of the parole board, said Brown’s right to privacy overrode the public interest of it being held as an open hearing.

He backed Brown’s Article 8 rights under the European Convention on Human Rights. A central part of the evidence will concern matters that not only affect the Article 8 rights of Mr Brown but also others who would not wish their right to privacy to be interfered with.

“If that evidence were to be revealed in public it may well affect Mr Brown’s ability to resettle in the community as well as affecting the right to privacy of others… I have balanced the Article 8 rights against the high interest in public justice.”

Diana Parkes, the mother of Joanna, said she was “angered” by the ruling.

“We have given up all our rights to privacy to do everything that we can to make sure this evil man stays behind bars,” she said.

“Why should Brown get to keep his privacy? I truly hope the Parole Board can still see that Brown is a dangerous man and does not let him out.

“Sadly, everything seems to be in favour of the perpetrator. The safety of the victims is put below the safety of the offender.”

Hetti Barkworth-Nanton, close friend of Joanna Simpson, said she was “totally shocked”.

“If the judicial system wants the public to see and believe that justice is done, then making Brown’s hearing private feels like a huge missed opportunity, especially as there has never been a public hearing of a ‘power to detain’ case.”