Iranian security forces said they arrested BBC correspondent Hassan Fathi for spreading false information and manipulating public opinion, state-funded broadcaster Press TV reports.
Heider Moslehi, the Iranian intelligence minister, said earlier this year that several people were arrested for giving anti-Iranian information to the British broadcaster.
"The government has found important information in light of the arrests, which serves as further evidence that political intelligence gathering is high on the BBC's agenda," he was quoted as saying.
The allegations come amid mounting criticism of Iran for its nuclear ambitions. The International Atomic Energy Agency said it found evidence that Tehran was working on some theoretical work for a weapon.
Ali Larijani, the Iranian speaker of Parliament, called on a national security committee to downgrade Tehran's diplomatic ties to London in light of the nuclear allegations.
British Foreign Secretary William Hague was quoted by The Daily Telegraph newspaper in London as saying the military option with the Iranian nuclear issue wasn't yet abandoned.
"We are not calling or advocating military action," he said. "At the same time we say all options should remain in future."