The Vatican helped secure the release of 15 British navy personnel detained by Iran in 2007, a U.S. envoy to the Holy See said in a document leaked by WikiLeaks and published Friday.
Julieta Noyes, U.S. deputy chief of mission to the Vatican, made the assertion in a classified cable dated June 26, 2009, intended to set the scene ahead of U.S. President Barack Obama's trip to Rome the following month.
Against a backdrop of deadly protests in Tehran over the re-election of Iranian President Mahmoud Ahmadinejad, she wrote: "It (the Vatican) has been publicly silent to date on the current crisis, in part to preserve its ability to act as an intermediary if an international crisis emerges.
"The Vatican helped secure the release of British sailors detained in Iranian waters in April 2007."
But she provided no further detail and added: "It is unclear how much clout the Vatican really has with Iran, however."
Iran seized the British sailors on March 23, 2007, while they were on patrol near the Shatt al-Arab waterway between Iraq and Iran.
It accused them of illegally entering Iranian territorial waters, a charge Britain denied, and only released them after 12 days in an incident widely viewed as humiliating for Britain.
A separate leaked U.S. cable dated April 2, 2007 -- right in the middle of the stand-off between Iran and Britain -- contains a commentary by a U.S. official about Tehran's intentions.
"Iran is using its seizure of the British sailors to prove its 'toughness', after facing repeated 'humiliations' on the international political front'," the official says.
But the official suggests Iran targeted British rather than U.S. military personnel because it would cause less of a global reaction.
Another cable dated April 11, 2007, says the British credited Oman with helping secure the sailors' release, after the foreign minister made regular calls to the Iranian authorities to urge they be freed.
The Foreign Office in London refused to comment on the leaked cables, which were published online by The Guardian, one of a number of newspapers worldwide that has been given access to about 250,000 files leaked by WikiLeaks.