U.S. prosecutors are considering whether to indict the brother of Afghan President Hamid Karzai for tax evasion, a leading American newspaper reported, citing officials familiar with the matter. The U.S. Attorney's Office in New York, aided by the Internal Revenue Service, has been examining the finances of Karzai's older brother, Mahmoud Karzai, a U.S. citizen, who says he hasn't been contacted by any federal authorities, according to The Washington Post. "I know myself. I'm very clean," the elder Karzai told the Post in a telephone interview from Kabul. A source familiar with the investigation told the Post a federal grand jury seated in New York was expected to indict Karzai. U.S. officials in Kabul said they were preparing for potential repercussions from the Afghan president if his brother is indicted. Hamid Karzai has complained that U.S. allegations of corruption against people close to him cloud his legitimacy as the country's leader and compromise Afghan sovereignty. Mahmoud Karzai, a former Baltimore restaurant owner, has been under scrutiny because of his role as the third biggest shareholder in Kabul Bank, which nearly collapsed in September. The Post reported the possible tax charges against him concern the sale of a villa in Dubai in 2008. Mahmoud Karzai, subject to U.S. tax laws because of his citizenship, said he recently paid the U.S. government $301,000 on the capital gains tax generated by the sale. "Whatever was due, I paid it," said Karzai, who now divides his time between Afghanistan and Dubai.