Four members of an anti-government group have been arrested on charges that include money laundering, tax evasion and weapons possession, federal prosecutors said Friday.

Authorities said the four men are members of the Sovereign Movement, a group that attempts to overthrow the government and defy authority with "paper terrorism." The arrests in Las Vegas on Thursday capped a three-year investigation into the group's activities led by the Nevada Joint Terrorism Task Force, U.S. Attorney for Nevada Greg Brower said.

A grand jury indictment in federal court in Las Vegas names Samuel Davis, 54, of Council, Idaho; Shawn Rice, 46, of Seligman, Arizona; Harold Call, 67, of Las Vegas; and Jan Lindsey, of Henderson, Nevada.

Davis and Rice are accused of laundering roughly $1.3 million for undercover FBI agents, who described the money as loot from a bank fraud scheme. Davis and Rice are charged with one count of conspiracy to commit money laundering and 30 counts of money laundering. If convicted, they face up to 20 years in prison and a $500,000 fine on each count.

Davis was described by prosecutors as a national leader in the Sovereign Movement, whose members believe government licenses, taxes and currency are invalid. Rice described himself as a lawyer and rabbi devoted to anti-government teaching, authorities said.

Davis and Rice pleaded not guilty in U.S. District Court in Las Vegas late Friday. Call and Lindsey also were due to appear in court. Authorities did not know if the four had lawyers.

Brower's office said Call and Lindsey, a retired FBI agent, are leaders of the Nevada Lawmen Group for Public Awareness, a group affiliated with the Sovereign Movement.

Call is accused of possessing an unregistered machine gun, as well as parts designed to convert manual firearms into automatic weapons.

He faces two counts of possession and transfer of a machine gun and three counts of possession of an unregistered machine gun. If convicted, he could get up to 10 years in prison and a $250,000 fine on each count.

Lindsey is charged with one count of evasion of payment of tax and four counts of evasion of assessment of tax. He faces up to five years in prison and a $250,000 fine on each count.