The end of the video showed a photograph of Representative Ed Royce, the California Republican who is chairman of the House Foreign Affairs Committee. Mr. Royce was quoted as saying that Iran’s arrest of Mr. Namazi showed its “contempt for America.”

Mr. Royce’s representatives in Washington said he had no comment on the video.

It was not clear when the video, released by the Mizan News Agency, which is affiliated with Iran’s judiciary, had been made.

But the timing roughly coincided with the first anniversary of Mr. Namazi’s arrest in Tehran, suggesting that formal charges were looming.

An international relations expert and business consultant with dual citizenship of the United States and Iran, Mr. Namazi is well connected in both countries and is an outspoken proponent of improving relations.

He had been a strategic planning executive at Crescent Petroleum, a privately owned Middle East energy concern, when he was arrested in Iran.