Tortured alliance

Documents found at the abandoned office of Libya’s former spymaster appear to provide new details of the close relations the Central Intelligence Agency shared with the Libyan intelligence service — most notably suggesting that the Americans sent terrorism suspects at least eight times for questioning in Libya despite that country’s reputation for torture.

Although it has been known that Western intelligence services began cooperating with Libya after it abandoned its program to build unconventional weapons in 2004, the files left behind as Tripoli fell to rebels show that the cooperation was much more extensive than generally known with both the C.I.A. and its British equivalent, MI-6.

Some documents indicate that the British agency was even willing to trace phone numbers for the Libyans, and another appears to be a proposed speech written by the Americans for Col. Muammar el-Qaddafi about renouncing unconventional weapons.

The documents were discovered Friday by journalists and Human Rights Watch. There were at least three binders of English-language documents, one marked C.I.A. and the other two marked MI-6, among a larger stash of documents in Arabic.

It was impossible to verify their authenticity, and none of them were written on letterhead. But the binders included some documents that made specific reference to the C.I.A., and their details seem consistent with what is known about the transfer of terrorism suspects abroad for interrogation and with other agency practices.

And although the scope of prisoner transfers to Libya has not been made public, news media reports have sometimes mentioned it as one country that the United States used as part of its much criticized rendition program for terrorism suspects.

A C.I.A. spokeswoman, Jennifer Youngblood, declined to comment on Friday on the documents. But she added: “It can’t come as a surprise that the Central Intelligence Agency works with foreign governments to help protect our country from terrorism and other deadly threats.”