It said the three men, who work for the Finnish-German company Nokia Siemens Networks in Dubai, were detained on Saturday off the island of Abu Musa and were being held in a secret location.

"We've been in contact with Iran and received information that all three are in good condition. We expect the issue to be resolved as soon as possible," a foreign ministry senior officer, Pasi Tuominen, told AFP.

He said Finland had not been informed of the formal charges against the trio.

Finnish Foreign Minister Ilka Kanerva said meanwhile the Finns may be released as early as Wednesday, Finnish news agency STT reported.

According to Esa Hurtig, Finland's charge d'affaires in the United Arab Emirates, efforts to obtain the trio's release have been hampered by a two-day holiday in Iran commemorating the death of Ayatollah Khomeini on June 4, 1989 and the uprising against the Shah on June 5, 1979.

Finland's ambassador to Tehran, Heikki Puurunen, was due to meet Iranian foreign ministry officials on Wednesday afternoon, STT said.

Nokia Siemens Networks confirmed the arrest of three of its employees but refused to disclose their identities, saying only they were "three men".

The three were arrested in a disputed area of the Gulf, at the mouth of the Strait of Hormuz that links the Persian Gulf to the Gulf of Oman.

Abu Musa is a contested island, claimed by both the United Arab Emirates and Iran due to its strategic location and potential oil reserves.