An Iranian-American scholar, Kian Tajbakhsh, who has been jailed in Iran since July and was sentenced last week to 15 years in prison, has been transferred back into solitary confinement, a family member said Wednesday. He has been in the infamous Evin prison for months but, he told his wife, was moved early this month from solitary confinement to a 'villa' on the prison grounds, living with four other high-profile inmates, according to the family member, who spoke on condition of anonymity for fear of complicating the case. A few days ago, Tajbakhsh was returned to solitary confinement, where prisoners often are forced to sleep on the floor. Tajbakhsh, an urban planner with a doctorate from Columbia University, was arrested after protests broke out following the disputed June 12 presidential election. The report of Tajbakhsh's transfer came as the government appeared to continue its attempts to forestall protests scheduled for next Wednesday, the anniversary of the U.S. Embassy takeover in Tehran. After arrests in the summer that stopped most large demonstrations, the opposition has been using occasions that the government supports to stage periodic rallies. On Wednesday, state television reported that Ayatollah Ali Khamenei, the country's supreme leader, said questioning the results of the election was 'the biggest crime.' It is unclear if that was anything more than a rhetorical flourish, but the timing suggests that it was a warning to protesters to stand down. Last week, the wives and family members of a number of high-profile political detainees were arrested at a religious ceremony in Tehran, and 19 of them continue to be held, reformist Web sites have reported. Tajbakhsh is one of more than 100 people being detained on election-related charges. According to his family member, he told his wife that he was taken to solitary confinement on Sunday to do 'some work.' In the past, prisoners have been kept in difficult conditions and asked to write confessions or to implicate fellow prisoners. Tajbakhsh was jailed for three months in the summer of 2007 on charges of trying to overthrow the government. Among the charges against him this time was that he worked as a consultant for the Open Society Institute, a democracy-building group that the indictment called a CIA satellite institution. 