WASHINGTON (AP):

The government is asking a federal judge for permission to go after at least US$226.6 million in back taxes, penalties and interest it says are owed by R. Allen Stanford, the Texas billionaire who has been accused of conducting an US$8-billion investment fraud through an offshore bank.

The Internal Revenue Service (IRS) tax agency on Friday filed a request with US District Judge David C. Godbey in Dallas to also order Stanford to file his income tax return for 2007 by April 15. Stanford and his wife, Susan, may owe taxes in addition to the US$226.6 million for 1999-2003, the IRS said in a court filing.

Stanford was charged with fraud last month by the Securities and Exchange Commission (SEC) in a civil proceeding. He has been ordered to surrender his passport but hasn't been charged with a crime.

Four tax liens

The IRS filed four tax liens against Stanford in 2007 and 2008. In August, the Stanfords requested a due-process hearing by the IRS's Office of Appeals to contest a lien filed in July for tax years 2002 and 2003 and a notice of intent to collect back taxes, the IRS said in its court filing. The IRS said the Stanfords also have contested the validity of what it says are their tax liabilities for those two years.

Stanford's personal fortune has been estimated at US$2.2 billion by Forbes magazine. His assets were frozen and put into receivership after the SEC lodged its civil complaint against him on February 17.

In an amended complaint filed February 27, the agency accused Stanford and his finance chief James M. Davis of conducting a "massive Ponzi scheme" through companies they controlled, including Antigua-based Stanford International Bank. In a Ponzi scheme, early investors are paid returns from money put in by later investors.

An attorney representing Stanford has said his client denies the allegations made by the SEC.