White House Farm killer Jeremy Bamber claims the investigators reviewing his conviction “have no compassion” and are full of lies.
He accused Criminal Cases Review Commission staff of having “no intention” of doing their job properly.
Bamber said the independent body had been sent new evidence which is “100% proof” he did not murder his family in 1985.
But he added he has waited over 400 days for a ruling on a new appeal.
After his case manager quit, Bamber, 61, claimed no “meaningful” probe had taken place because of “pressure” from police, the Crown Prosecution Service and the Government.
He is serving a whole-life sentence for the murder of his adoptive parents Nevill and June, both 61, his sister Sheila Caffell, 26, and her six-year-old twins Daniel and Nicholas.
Bamber claims Sheila, who suffered from schizophrenia, shot the family before turning the gun on herself.
In letters sent from his prison cell, Bamber wrote: “Our case manager is resigning, all of those last 6/7 months waiting for an update on my case.
“Investigations have been for nothing. All those lies, ‘I’ll give you an update in a few weeks’, it was bulls***t.
“[They] had no intention of tackling my case. Typical of the case managers I’ve had over the last 20 years.
“None have been helpful or neutral managers of my case.
“It seems… [they] do nothing and waffle and lie is the order of the day. The CCRC need to get a grip of my miscarriage of justice and do the job they were set up to do. Maybe my new case manager will do just that. It’s not hard, but pressure from the police/CPS/Home Office I bet is huge. We battle on.”
Bamber was convicted in 1986 of the massacre at White House Farm near Tolleshunt D’Arcy, Essex.
He was granted an appeal in 2002 after the CCRC referred his case, but it was dismissed. Last year he claimed his legal team had identified eight issues which he hoped would prove his innocence.
In letters to Rory Everett, owner of memorabilia firm Dark Crime Collectables, Bamber, who is in Wakefield prison in West
Yorkshire, wrote: “I’ve been feeling annoyed with the CCRC. They promise a response which is meaningful every three months.
“The CCRC have had proof of my innocence on their desk since Christmas, 100% proof. It has been six months since the CCRC have said a word to us and 400 days plus since we sent in our application for an appeal. The CCRC appear to have no compassion.”
The letters will be made available on the Dark Crime Collectables website, with a price to be set.
The CCRC said it received Bamber’s application in March 2021, adding: “We continue to conduct a thorough, totally independent review and have provided regular updates to his legal representatives – the last of which was on June 24.
“This is a complex case with continuing submissions from Mr Bamber’s team. However, this adds to the time it is taking to review.”