Neither the man's identity nor the country for which he was allegedly working were named.
"The suspect is accused of spying for a foreign country in order to damage the political and military status of the United Arab Emirates," WAM quoted Prosecutor General Ahmad al-Danhani as saying.
"He had allegedly been exploiting his job at one of the country's ports and was seeking to illegally obtain military information considered among the national security secrets of the UAE," the news agency added.
The man has been referred to the public prosecution and is under arrest as the investigation continues, Danhani said, without giving more details.
Last September, an Emirati court jailed a Pakistani man for three years for spying for an unnamed foreign country.
And in January 2013, an Emirati married to an Iranian woman was sentenced to seven years for spying.