The family of murdered private investigator Daniel Morgan aim to sue the Met police after a landmark report found a “cover-up at the highest ranks”.
An independent panel accused the force of “institutional corruption” for hiding failings in a string of probes into the unsolved killing.
The dad-of-two, 37, was attacked with an axe in the car park of the Golden Lion pub in Sydenham, South London, on March 10, 1987.
Five police inquiries, costing the taxpayer an estimated £30million, have failed to obtain a single conviction and Mr Morgan’s family have battled for justice for 34 years.
They said in a statement: “Three generations of our family have already suffered as the collateral damage resulting from the inexcusable failure of the institutions of the state to do what was required of them in the face of institutionalised police corruption.
“We do not want this burden to be passed on to the coming generations of our family.” They said they had been forced to bring a civil claim in order to achieve some “semblance of accountability”.
In June panel chairwoman Baroness Nuala O’Loan said the Met’s first objective was to “protect itself” by refusing to acknowledge its many failings since Mr Morgan’s murder.
She also accused Met Commissioner Dame Cressida Dick of adding to the Morgan family’s pain by delaying the inquiry.
Dame Cressida apologised to the family but rejected the finding her force was “institutionally corrupt”. Solicitor Raju Bhatt has confirmed that a letter of claim had been sent.
The Morgan family statement said: “We have been saddened – if not surprised – to find we have been let down yet again by all concerned.”
A spokesman for the Met said: “We can confirm that the Metropolitan Police Service has received a letter of claim, dated 7 December, and is currently considering its response.
“Since the Daniel Morgan Independent Panel published its report six months ago, a dedicated team within the Met has been established and is progressing its response to those recommendations specific to the Met, while engaging with other lead organisations named in the report.”