Tehran - An Iranian-American reporter detained in Tehran for alleged illegal press activities has been charged with espionage, local media reported Wednesday.

Roxana Saberi, 31, a reporter for US-based National Public Radio (NPR), was initially detained for buying alcohol and has been held in Tehran's Evin prison since the end of January.

In March, Foreign Ministry spokesman Hassan Ghashghavi said Saberi was denied official press accreditation since 2006 and was working illegally.

"Without having press credentials, she was carrying out spying activities under the title of a journalist," Tehran's deputy prosecutor Hassan Haddad was quoted as saying by Student's News Agency ISNA.

Haddad said her case was sent to the revolutionary court, and claimed that "she has accepted all charges."

"We are deeply concerned by the news that we're hearing," US Secretary of State Hillary Rodham Clinton said in Washington. "We have asked the Swiss, who, as you know, are our protectorate in Iran, to obtain the most accurate, up-to-date information.

"I will ... continue to follow this very closely. And we wish for her speedy release and return to her family."

The release of Saberi and an inquiry about the long-missing US citizen Robert Levinson, a former Federal Bureau of Investigation agent, were mentioned in a letter from Clinton to the Iran government, during an international conference on Afghanistan in The Hague last month.

Saberi has lived in Iran for the past six years and reported for NPR, and broadcasters ABC and BBC. Before her arrest, she was pursuing a master's degree in Iranian studies and international relations and writing a book about Iran. (dpa)