The Court of Appeal in Belfast has ruled that the PSNImust carry out a criminal investigation into the treatment in custody of the "Hooded Men" in 1971.
In their majority ruling the judges said that the treatment of Francis McGuigan and fellow detainee Seán McKenna "would, if it occurred today, properly be characterised as torture".
The ruling then agrees that an investigation carried out by the Historical Enquiries Team was "irrational and did not honour the undertaking given by the Chief Constable.
"In light of the manner in which the investigation was pursued it seems unlikely that an investigation by the Legacy Investigation Branch of the PSNI or its successor is likely to engender public confidence".
Darragh Mackin of Belfast-based human rights firm Phoenix Law, who is representing Francis McGuigan (pictured) welcomed the "significant" ruling.
A controversial European Court of Human Rights (ECHR) judgment in 1978, which said the "five techniques" used during the men’s interrogation was not torture.
Darragh Mackin said: "Today is significant as the court firmly said that the rule of law is undermined if that extends to protecting ministers from investigation in respect of criminal offences committed by them.
"It is now essential that an effective and independent investigation is commissioned without any further delay."
Francis McGuigan said "Today's judgment makes it expressly clear that the treatment that I suffered at the hands of ministers was torture and should be investigated by an independent police force.
"This treatment cannot be forgotten. It has had lasting and terrible effects on my mental health to this day and I can only hope that this judgment will assist someone somewhere in the world that suffers torture at the hand of their Government."
The 14 Catholic men were interned without trial and tortured under five categories: hooding, stress positions, white noise, sleep deprivation and deprivation of food and water.
They were also beaten and threatened with death.
The men were hooded and flown by helicopter to a British Army camp at Ballykelly, outside Derry, though they didn’t know their location at the time.
They were also dangled out of the helicopter and told they were high in the air although this was not the case.
Nobody was convicted of any wrongdoing in this case.