REPORTS that “Jihadi John”, a particularly ghastly member of the Islamic State who has been identified as the beheader of at least five Western hostages in Syria, is a Briton named Mohammed Emwazi embarrassed several outfits. One of them was MI5, Britain’s domestic security service, which had apparently interviewed him but then let him slip out of Britain. Another was Cage, a British Islamist outfit which had warm relations with Mr Emwazi. But the twitchiest reaction was at Amnesty International.

Cage caused the rumpus after one of its leading lights described Mr Emwazi as “kind”, “gentle” and “a beautiful young man”. Mr Emwazi’s crimes, he explained, were partly due to harassment by MI5, which got onto Mr Emwazi in 2009 after he had been arrested in Tanzania, probably on his way to wage jihad in Somalia. Cage was widely barracked for that insinuation. And then so was Amnesty, because of its links to Cage.

Amnesty was founded in 1961 with a mission to campaign for “prisoners of conscience”, defined as those who have been locked up for expressing their views—emphatically without advocating violence. Since then it has grown into a huge organisation with more than 70 national chapters. Many thousands of prisoners and people persecuted for their beliefs have benefited from Amnesty’s courageous moral and practical support over the years. In 1977 it won the Nobel peace prize.

In the past decade or so Amnesty has widened its brief from human rights and torture into such matters as how to reduce poverty and limit the arms trade. (By contrast, Human Rights Watch, a pre-eminent New York-based monitoring group, has stuck closely to the mission for which it is named.) Amnesty has forged alliances and shared platforms with groups which do not necessarily share its original aims.

Controversy over Amnesty’s relations with Cage goes back five years, when Gita Sahgal, a senior figure in Amnesty, was sacked for criticising her organisation’s close ties to Moazzam Begg, a British former detainee of the Americans in Afghanistan and then in Guantánamo, and a director of Cage (formerly Cageprisoners).

Cage describes itself as “an independent advocacy organisation working to empower communities impacted by the war on terror.” Ms Sahgal, however, has long argued that Cage is by no means a human-rights group but a promoter of violent jihad against the West and against non-Islamists in general. She has derided a claim by another former senior Amnesty figure a few years ago that Cage’s promotion of “defensive jihad” is “not antithetical to human rights”.

Ms Sahgal, who later co-founded a group called the Centre for Secular Space, returned to the fray this month after the revelation of Cage’s connection to Mr Emwazi and its blaming of MI5 for his radicalisation and brutality. She also chided Amnesty International for letting Cage (along with seven other human-rights groups) co-sign a letter in December to David Cameron, the prime minister, calling for a judge-led inquiry into Britain’s alleged involvement in the rendition and torture of Islamist terrorist suspects.

Far from being a genuine human-rights group, says Ms Sahgal, Cage is “completely poisonous”, promoting an ideology that mocks the values of tolerance, especially towards women. “Immense damage has been done to Amnesty,” she says, “not least because they won’t come clean about their association with Cage.” Yet Amnesty has “taken their research from them, they have shared logos with them, they have produced briefing papers together, signed letters to the government together.”

Amnesty hotly denies it is too close to Cage or endorses its ideology, though a spokesman says it is “highly unlikely” it would now sign a joint letter with it. Still, Amnesty may need to ponder the scope of its advocacy and the sort of allies with whom it is willing to team up. Some “agonising” is said to be taking place. Lord (Alex) Carlile, a long-term Amnesty supporter who for more than nine years was Britain’s Independent Reviewer of Terrorism Legislation, said the organisation had been “extremely unwise and lacking in critical faculty” by associating itself with Cage, whose reputation had been “damaged beyond repair”. Amnesty’s, he reckons, could be rescued, but it must hurry.