http://news.bbc.co.uk/1/hi/uk_politics/6915652.stm The cross-party committee said "routine" evidence sharing in the case of two British residents in Ghana in 2002 "indirectly and inadvertently" led to their rendition.
Bisher al-Rawi and Jamil el-Banna were flown by the CIA first to Afghanistan and then Guantanamo Bay, where el-Banna is still being held.
The committee said the UK services "used caveats specifically prohibiting any action being taken" when they handed over the intelligence on the men.
It says the UK security services did not foresee that the US authorities would disregard the caveats, given that they had honoured the caveat system for the past 20 years.
"This case shows a lack of regard on the part of the US for UK concerns - despite strong protests - and that has serious implications for the intelligence relationship," the report concluded.
Because we really needed this report to tell us that.