John O’Hara, a 41-year-old father-of-five, was shot dead by members of the Ulster Defence Association (UDA) as he arrived to collect a fare on Dunluce Avenue in February 1991.

Mrs Anderson concluded that the original Royal Ulster Constabulary (RUC) investigation “failed to effectively pursue relevant suspects”.

Although the RUC had no advance intelligence that might have allowed it to prevent the killing, Mrs Anderson said that serious investigative shortcomings followed the initial response.

Her office began the review after receiving a complaint from Mr O’Hara’s family. Mrs Anderson said: “Although the initial police response was comprehensive and of a good standard, the subsequent murder enquiry was not capable of bringing those responsible to justice.”

Within a fortnight of the killing, police received intelligence naming eight individuals allegedly linked to the murder. O those, however, only three were arrested — and there is no evidence that the alibis they offered were ever verified.

In addition, two firearms used in the attack — recovered in 1992 and 1995 — can no longer be located. No documentation exists to show that the weapons were lawfully disposed of.

Mrs Anderson said they should have been retained “for evidential purposes in respect of unsolved murders, including Mr O’Hara’s”.

The victim’s family welcomed the findings. Their solicitor, Pádraig Ó Muirigh, said: “These findings are a damning indictment of the RUC investigation into John O’Hara’s murder.”

He added: “The breadth and nature of these failings cannot be explained by mere incompetence. The O’Hara family have a long-held view that those involved in the murder were protected from prosecution by the RUC. That view has been reinforced by these findings.”