The ruling by the European Court of Human Rights prompted a chorus of calls for a wider inquiry to be called.
Both Sinn Féin and the SDLP said the decision by the highest court in Europe strengthened demands for a full judicial inquiry.
The SDLP's justice spokesman, Mr Alban Maginness, said the verdict came as "no real surprise".
He said: "Other cases have come before the European Court of Human Rights and the same conclusion that they were not properly investigated was reached. The PSNI and the Policing Board have now laid down mechanisms to ensure that murders are properly investigated, resourced, and reviewed - the failures of the past will not be repeated in the future." He added that the decision "only confirms and further strengthens the case for a full judicial inquiry into the murder of Pat Finucane - a case the SDLP will continue to pursue."
Mr Mitchel McLaughlin, the Sinn Féin chairman, said: "The identities of those involved in the killing of Pat Finucane are well known.
"The fact that agencies of the British state used the UDA to carry out this killing is beyond doubt. What is required now is a full, independent judicial inquiry to establish exactly who authorised and planned this killing and where the chain of command leads to."
Human rights organisations presented a united call for a public inquiry: "It is time the \ government stopped aiding and abetting those who have engaged in collusion and cover-ups and allowed the full truth to be told about this case by establishing a public inquiry."
In a detailed statement, Amnesty International, the Committee on the Administration of Justice and British-Irish Rights Watch said the British government should take immediate action to give effect to the European court's findings.
The organisations called for the full publication of all three investigations carried out by Sir John Stevens, the commissioner of London's Metropolitan Police.
They also called on the government to ensure the DPP "gives full explanations for the many controversial decisions that have been made in relation to the Finucane case" and to establish an independent, international public inquiry with full judicial powers of discovery and subpoena.
A spokesman for the three organisations said: "This judgment confirms that there has been no effective investigation of the collusion in this murder. The Finucane family have been waiting for 14 years for justice."
The Northern Ireland Office issued a brief statement saying: "The government takes European Court decisions very seriously and will want to give careful consideration to this decision."
One reliable British source admitted the judgment added to the pressure over the Finucane case but suggested the government would still await the findings of Judge Peter Cory, a retired Canadian judge.
The Irish Times understands he has completed his inquiries into the Finucane killing and is now concentrating on other murders. He is expected to report to the British government in October.