An Iranian-American businessman detained in Iran since October has been denied access to his lawyer by authorities, his attorney and family said in an interview and on social media over the last two days.Siamak Namazi, a dual US-Iranian citizen, was detained by Iran's Islamic Revolutionary Guard Corps in October while visiting family, according to a source familiar with the matter who declined to be identified. Iranian authorities have not announced any charges against him.Five other American citizens were released from Iranian prisons more than a month ago as part of an historic prisoner swap with the United States. After their release, US Secretary of State John Kerry said that he had commitments from Iran that Namazi's case would be resolved soon.Mahmoud Alizadeh Tabatabaei said in a phone interview on Friday that he is representing Namazi and that Iran's judiciary chief has not yet allowed him to meet with his client. Such permission is required by Iranian law if an individual is accused of national security-related crimes, he said, adding that he has not been officially informed of Namazi's charges."Not me, nor any other lawyer has received such permission from the head of judiciary so far," Tabatabaei said. "His mother has met him a few times, but his father has not been allowed to see him."