Marc Emery, 47, of Vancouver, British Columbia, is charged with conspiracy to launder money and distribute marijuana and marijuana seeds, the U.S. attorney's office said. Conviction on the charges would carry a sentence of at least 10 years in prison.

Emery claims to make $3 million a year from selling marijuana seeds online and by mail, along with equipment for grow operations and instructions on raising pot plants, authorities said. He was arrested in Nova Scotia by the Royal Canadian Mounted Police.

Prosecutors say three-fourths of Emery's seeds are sent to the United States and have been linked to illegal grow operations in Indiana, Florida, California, Tennessee, Montana, Virginia, Michigan, New Jersey and North Dakota.

American authorities said Emery's arrest followed an 18-month undercover investigation during which he sold seeds to Drug Enforcement Administration agents, by mail and in person.

His Web site boasted "the largest selection of marijuana seeds in the world," including more than 600 strains from dozens of suppliers.

Rod Benson, the DEA's Seattle special agent in charge, told a Friday news conference here that Emery showed "overwhelming arrogance and abuse of the rule of law."

Emery's Web site became inaccessible Friday afternoon, displaying only a message in large red script that said: "Emery Seeds has been raided by the DEA and is shut down."

Some of Emery's seeds went to people growing pot for their own use, said Jeff Sullivan, chief of the criminal division for the U.S. attorney's Seattle office.

"However, a substantial amount was going to commercial marijuana operations, and we think they'll be significantly affected once he's out of business," Sullivan said.

Emery is a leading figure in the B.C. Marijuana Party, which has run candidates for legislative office. He also publishes the magazine Cannabis Culture, which said Emery has twice run for mayor of Vancouver.

The indictment came out of Seattle because DEA officials here led the investigation, and there was evidence that Emery committed some crimes in the Western Washington federal judicial district, U.S. attorney's spokeswoman Emily Langlie said.

A grand jury in Seattle indicted Emery on May 26, along with Gregory Williams, 50, and Michelle Rainey-Fenkarek, 34, both of Vancouver. Authorities said Williams and Rainey-Fenkarek were arrested Friday in Vancouver; they face the same charges.

Search warrants also were issued in Vancouver for Emery's home, his office and a storefront business, Sullivan said. Court documents listed "Prince of Pot" as an alias for him.

A warrant for Emery's store - called Toker's Bowl - asked Vancouver police to seize a long list of items on behalf of U.S. authorities, including cash, client lists, employee files and computer records, Canadian Press reported.

The shop is next door to the New Amsterdam Cafe, where patrons are known to openly smoke pot. Several people, some holding signs with anti-American slogans, gathered outside Friday to protest the raid.

Emery's magazine said he served 61 days in jail last fall for possessing marijuana at a gathering with students after a speech at the University of Saskatchewan. Canadian Press said it was his 11th drug-related conviction, but the first time he was sentenced to jail.