Similar raids have been made this year against alleged Islamic extremists in Gothenburg and Malmö, but news of the Stockholm action has only just emerged.
Chris Hilton, spokesman for the British Embassy, confirmed on Wednesday that the Metropolitan Police in London had requested the action from their Swedish counterparts.
“The Metropolitan Police Service is working jointly with Swedish police as part of an ongoing investigation,” he said to The Local.
Swedish police are referring all questions on the matter to prosecutors. Agneta Hilding Qvarnström at the international prosecutor’s office in Stockholm says she can only confirm that the Swedish police carried out the raids after requests for help from British police.
It is understood that the raids were requested by counter-terrorism police, but this has not been officially confirmed by Swedish or British authorities.
Reports of both the Gothenburg and Stockholm raids said that police seized laptop computers. Police in Gothenburg also took books and a mobile phone, reports at the time indicated.
Following the Stockholm raid, Solna district court decided to allow the “applicant state” to take the seized material.
In April, police called a 43-year old man in for questioning, also following what is understood to have been a British a request for help. Interview records were then handed over to the British following a decision from Solna district court.
A Gothenburg resident, Abu Usama el-Swede, 28, was questioned along with two others following a raid on his home at the end of May, it was reported in Aftonbladet. Four men were detained by police following the raids in Malmö, but few further details were forthcoming.