WASHINGTON: The United States said on Wednesday it is asking other countries to help find out what may have happened to a former FBI agent missing in Iran. Washington has not had formal diplomatic relations with Tehran since 1980, when it cut ties after the Iranian revolution and the holding of American hostages.

Florida resident Robert Levinson went missing while on a visit to the Gulf island of Kish in Iran early in March.

US officials have said they believe he is in Iran but have no credible information about his exact whereabouts. It is not clear why Levinson visited Iran.

Diplomats fear the case of Levinson could mark a new twist in a series of detentions involving the United States, Britain and Iran, which began with the holding of five Iranians by USforces in Iraq in January and the capture by Iran of 15 British sailors who were freed earlier this month.

There are also heightened tensions over Iran's nuclear programme, with Washington having spearheaded UN sanctions against Tehran. The US State Department said it was approaching other nations, which it declined to name, because it had yet to get a satisfactory response to its own inquiry to Iran's government.—Reuters