The High Court in Belfast has ruled that the UK government’s refusal to hold a public inquiry into the murder of Belfast solicitor Pat Finucane was lawful.

His widow, Geraldine Finucane, brought a judicial review against the government after it refused to hold a statutory inquiry into the 1989 murder, in which it is alleged British security forces colluded with loyalist paramilitaries.

Prime Minister David Cameron previously acknowledged “shocking levels of collusion” after the UK government published the results of a review conducted by Sir Desmond de Silva.

However, Mr Finucane’s family said the 2012 review was a “sham” that fell short of a full public inquiry.

Mrs Finucane, who was not in court when the judgement was read out, believed the decision not to hold an inquiry was indefensible.

Making his judgement on Friday, Mr Justice Stephens said: “I uphold that the decision was lawful and accordingly I dismiss that part of the challenge.”

The judge also said an inquiry would be “protracted and long”.

John Finucane, the deceased solicitor’s son, told the Irish Independent that the family had not yet decided whether to appeal the judgement.

However, the Government of Ireland has agreed to continue pushing for a full public inquiry into Mr Finucane’s death.

Foreign affairs minister Charlie Flanagan said: “My thoughts at this time are with Geraldine Finucane and all the Finucane family, who have campaigned so tirelessly for more than a quarter of a century in pursuit of the full truth in the case of Pat Finucane, including the role of collusion in his murder.”