A federal grand jury in Anchorage indicted four men Friday on a charge of conspiracy to defraud the government, accusing them of filing false income tax returns, many for prisoners, and splitting the refunds among themselves and others, according to the indictment.

The indictment said that between September 2008 and May 2012, Jesse Wilson, 41, of Alaska, William "Speedy" Hines, 54, of Alaska, Jason Schmidlkofer, 34, of Alaska, Nick Thurmond, 30, of Colorado, "and others" prepared and mailed about 375 false tax returns using the names and Social Security numbers for about 185 people, many of whom were in jail.

"Each return claimed that the taxpayer was owed thousands of dollars in refunds to which they were not entitled," said a statement from the office of U.S. Attorney Karen Loeffler.

The claims totaled about $580,912, of which the U.S. Treasury paid about $380,605, said the indictment filed in the U.S. District Court of Alaska.

Some of the refunds were issued by paper checks; others were directly deposited into bank accounts. Once the refunds were deposited into the bank, the men and others made cash withdrawals or wired the funds to other accounts, according to the indictment.

If found guilty, the men face up to 10 years in jail and a $250,000 fine.