Iran has released three Belgians who were detained two months ago for allegedly entering a prohibited area and gathering information, Iranian state televison has said.

The IRNA news agency said the three men were released and handed over on Tuesday to the Belgian ambassador in Tehran on the orders of Abbas Jafari Dolatabadi, a prosecutor in the capital.

Dolatabadi was quoted as saying that the three men, identified as Van den Bosch, Vincent Binfleur, and Diego Gomatio, were detained for "entering a prohibited area and gathering intelligence".

Wednesday's report gave no details about when or where they were arrested and the detentions had not been previously reported in Iran.

Belgium's foreign ministry declined to comment on the case.

Iran is embroiled in a long-running dispute with Western powers over its nuclear programme, accusing the Islamic Republic of attempting to build a nuclear bomb, a charge Tehran denies.