The Associated Press
By DESMOND BUTLER
A relative says security forces arrested Kian Tajbakhsh late Thursday. The relative was in contact with Tajbakhsh's wife, who witnessed the arrest.
There was no independent confirmation from Iranian authorities. The relative spoke to The Associated Press on condition of anonymity because of concern that public comments could aggravate Tajbakhsh's situation.
Tajbakhsh spent four months in prison in 2007 on charges of endangering national security. He denied the allegations.
Tehran has seen massive demonstrations following disputed June 12 presidential elections.