Image copyright Other Image caption Kamel Bourgass (L) and Tanvir Hussain (R)

Two convicted terrorists who claimed their prison segregation was unlawful have won their challenge at the UK's highest court.

Kamel Bourgass and Tanvir Hussain were separated from other inmates for up to seven months after being accused of faith-related attacks.

The Court of Appeal rejected the claim but the Supreme Court has overruled it.

Hussain was jailed for his role in the 2006 airline bomb plot. Bourgass was implicated in a ricin poison plot.

The men were kept in solitary confinement after being accused of attacks on other inmates.

But the pair, who both denied the allegations, argued that it was illegal for prison staff to order their segregation for more than 72 hours without permission from ministers.

The Supreme Court unanimously found in the two men's favour on the domestic legislation governing segregation, but rejected the men's claim that their human rights had been violated.

Analysis

By Clive Coleman, legal affairs correspondent

The judgment turned on the fact that the decisions to segregate Hussain and Bourgass beyond 72 hours were taken within the prisons themselves.

The Supreme Court found the segregations were unlawful because the law makes clear that in order to protect prisoners, any decision to segregate beyond 72 hours should be taken independently by the Secretary of State for Justice or his officials, and not by local prison management.

A human rights challenge based on the men's right to an independent hearing on the segregation decisions failed.

So this was not a human rights victory for prisoners, far from it.

This was about the interpretation of home-grown legislation and whether the practice currently being applied in prisons was compatible with it. It wasn't, and will now have to be changed to become compatible.

Bourgass, an Algerian, is serving 17 years for his involvement in the 2002 ricin terrorist plot.

He is also serving a life sentence for murdering Detective Constable Stephen Oake with a kitchen knife during his 2003 arrest at a flat in Manchester.

In 2009, while at HMP Whitemoor in Cambridgeshire, authorities feared he was bullying and intimidating fellow prisoners and they recorded "an escalation of violence [in the prison] for faith-related reasons".

He was not charged with an offence - but was placed in segregation for approximately five months.

Hussain was jailed in 2009 for a minimum of 32 years over his role in the 2006 liquid bomb plot - which resulted in immediate worldwide restrictions on passengers carrying liquids in their hand luggage.

While at HMP Frankland in County Durham, he was involved in a serious attack on another prisoner who received wounds to his face.

Prison intelligence suggested he was playing a wider role in the "conditioning" other vulnerable prisoners. He was kept in solitary confinement from April to October 2010.

Prison rules

Prison rules allow a prison governor to order segregation, but the prisoner cannot be segregated for more than 72 hours without the authority of the secretary of state.

This can be authorised for a period of no more than 14 days, but can be renewed.

For several years, however, this has been done by governors or prison officers, according to the BBC's legal correspondent Clive Coleman.

The men's appeals were unanimously allowed in relation to the practice of segregation beyond the first 72 hours authorised by governors and also in relation to the fairness of their treatment under common law.

Under common law they should have been better informed of the basis for their segregation, the court ruled.