The raid by US special forces in Syria that killed an Islamic State official also secured a significant amount of intelligence material, members of Congress who were briefed on the operation claimed on Sunday.

Senior figures on congressional committees on intelligence and security said the discovery was potentially more significant than the killing of Abu Sayyaf, who the Obama administration says led the terrorist network’s lucrative oil sales operation.

Michael McCaul, the Texas Republican who chairs the House homeland security committee, said computers and paperwork scooped up from the site in eastern Syria on Friday night would help US officials learn “where the tentacles reach” from the Isis leadership.

“We discovered a treasure trove of electronic information, and documents and records relating to the organisational structure of Isis, which will help us long term in taking out the command and control structure,” McCaul told Fox News Sunday.



On CNN Adam Schiff, the top Democrat on the House intelligence committee, described the material seized as “an important yield”, adding it could “present great value”.

Sayyaf’s wife, Umm Sayyaf, was being questioned in Iraq following her capture in the raid, which the White House said had resulted in the freeing of a young Yazidi woman “who appears to have been held as a slave by the couple”.

Unidentified US officials told both ABC and CBS interrogators were particularly keen to ask Umm Sayyaf about the captivity and mistreatment of Kayla Mueller, a young American aid worker who died earlier this year during her detention by the Islamic State.

Reuters reported that the Syrian Observatory for Human Rights, a British group which gathers information from sources in the region, had concluded on Sunday that at least 32 Islamic State members, including four senior officials, had been killed by the raid and accompanying air strikes.

Amid doubts raised by analysts about the seniority of Abu Sayyaf, congressional figures insisted he was the primary target of the operation and that his death had made the high-risk mission worthwhile.

“This is the guy that we were trying to get,” said Schiff.

McCaul described Sayyaf as “the chief financial officer of Isis”.

US raid kills senior Isis leader – video report. Guardian

Speaking on ABC, Dianne Feinstein, the senior Democrat on the Senate intelligence committee, claimed the strike was a “picture-perfect raid” and urged the administration to mount more special operations in the region.

However, Schiff urged caution against escalation, saying that while the administration had clearly decided the value of intelligence gained by the raid was “sufficient to merit that kind of risk”, it should not signal the start of a wave of similar operations.

“Nonetheless, this was an extraordinary risk and if one of our people were captured, if we’d lost one of our special forces, there would be tough questions to answer about whether it was worth it,” he said.