The brother of a private detective brutally killed in a notorious case linked to police corruption has vowed to keep fighting for justice.

Alastair Morgan and his family are still determined to secure a judicial inquiry into the police’s handling of the 1987 murder of his brother Daniel – which has been the subject of five failed probes – despite feeling knocked back by Home Secretary Theresa May last month.

The family were offered yet another police investigation after meeting with the Conservative minister at the Home Office, accompanied by Islington South and Finsbury MP Emily Thornberry.

Mr Morgan, of Gee Street, Finsbury, told the Gazette: “She suggested there should be another police investigation, but we know the British police by this time and have seen enough of their antics.

“Theresa May does not appreciate the risk this poses to future police investigations. It shows they can do whatever they like. The handling of the case needs urgent and rigorous scrutiny to return any kind of confidence in the police.”

Daniel Morgan was found dead with an axe lodged in his head in a south London pub car park in 1987. The Metropolitan Police has apologised to the family after admitting corruption in the original police probe was a major factor in the ongoing failure to secure any convictions.

Alastair Morgan added that the family is considering its next move, saying: “All we have had is 25 years of failure and corruption and waste of public money, but this is not over by any means. We’re considering all our legal and political options.”

A Home Office spokesman said: “It is deeply regrettable that Daniel Morgan’s killers have not been brought to justice and we understand the strength of feeling this case has caused.

“The Metropolitan Police and the Crown Prosecution Service are currently conducting internal investigations into the case and we expect their findings shortly.”