The best friend of a woman who was killed by her husband 13 years ago has said her friends and family must “plan for the worst” as his automatic release from prison draws nearer.

Joanna Simpson was killed by British Airways captain Robert Brown at their family home in October 2010.

Relatives and friends have urged Justice Secretary Alex Chalk to use new powers which could stop Brown being released automatically and instead get the case reviewed by the Parole Board.

Brown was cleared of murder, having admitted manslaughter on the grounds of diminished responsibility, and is likely to be released in November after serving 13 years of a 26-year sentence.

Joanna Simpson murder
Robert Brown is due to be released in November (Thames Valley Police/PA)

Mr Chalk agreed to meet Ms Simpson’s family earlier this year to discuss the killer’s release.

Her best friend Hetti Barkworth-Nanton, who also chairs domestic abuse charity Refuge, told BBC Breakfast that the prospect of Brown’s release feels “very, very real” and has left her feeling “physically sick”.

She told the programme: “It is terrifying, absolutely terrifying. It is his legal right to be let out of prison unless the Lord Chancellor intervenes with the new power that he was given last year.

“We are all just emotionally exhausted and we continue to fight because we have to fight to protect us, but also to protect the general public but it is exhausting, absolutely exhausting.”

When asked if she still has hope his automatic release could be blocked, she said: “I am determined to retain the hope.

Sunday with Laura Kuenssberg
Justice Secretary Alex Chalk is considering the case (Lucy North/PA)

“It is hard when you are facing the reality of endless conversations with the victim liaison team in probation talking about licence conditions and how they may go about trying to protect you, so we have to plan for the worst but we have to retain hope for the best and hope that the Lord Chancellor will use his powers.

“This isn’t us trying to block a parole decision where the Parole Board is saying there is no risk to the public.

“There absolutely is risk to the public, but it doesn’t refer to the Parole Board, he is automatically let out.

“He has been refused access to an open prison because he is deemed a risk, he has been categorised as a critical public protection case because he is a risk.

“It shouldn’t be the case that our sentencing laws in these very serious, very callous killings, rely on family and friends of people who have been viciously killed to have to campaign openly in the public to get the right action happening.”

Ms Simpon’s mother Diana Parkes told the broadcaster in a pre-recorded interview that it is “essential for all of us” that Brown remains in prison.

She added: “He actually brutally killed her with a claw hammer, 14 times hitting her on the head. That is so evil.

“He is toxic, he’s a bully, he just should not be let out of prison.”

A Ministry of Justice spokesperson said: “Joanna Simpson was brutally killed in a cowardly, senseless attack and needlessly taken from her family.

“The Lord Chancellor met with her loved ones in May and, as he reiterated on Sunday, will continue to give this case his close personal attention.”

Brown, formerly of Winkfield in Berkshire, was sentenced to 24 years for manslaughter and a further two years for an offence of obstructing a coroner in the execution of his duty.

He killed his wife as their two young children cowered in a playroom, before dumping her body in a makeshift coffin in Windsor Great Park.