An Iranian diplomat seized two months ago in Iraq by uniformed gunmen has been freed.
In Baghdad, an Iraqi official said his government had exerted pressure on those holding the Jalal Sharafi to gain his release.
Mr Sharafi was seized on February 4th by uniformed gunmen in Karradah, a Shia-controlled district of Baghdad.
Iran contended he had been seized by an Iraqi military unit commanded by US military forces - a charge repeated by several Iraqi Shia lawmakers. But US authorities denied any role in his disappearance.
Officials would not say if the release of Mr Sharafi was linked directly to Britain's efforts to gain the release of 15 sailors and marines held by Iran. Britain has publicly sworn not to negotiate.
But the move seemed certain to increase the likelihood that Iran - which has been highly agitated by its diplomats' detention - would look more favourably on releasing some of the captured Britons.
Prime Minister Tony Blair told reporters in Scotland that the next two days would be "fairly critical" to resolving the stand-off over the navy crew, although he gave no details what he meant.