Marc Emery, 52, will receive a five-year sentence after pleading guilty to drug charges in the U.S.
Canada's self-styled "Prince of Pot" has been knocked from his throne.
Marc Emery will be heading to prison after pleading guilty Monday to selling marijuana seeds from Canada to customers in the United States, under an agreement with U.S. prosecutors.
The 52-year-old will receive a five-year prison sentence in exchange for his admission in U.S. District Court in Seattle to one count of conspiracy to manufacture marijuana.
"Sometimes you reap what you sow," U.S. Attorney Jenny A. Durkan said Monday in a news release from the U.S. Department of Justice.
"Seeds from Marc Emery's business were found at grow sites across the United States. Mr. Emery made millions of dollars promoting and facilitating marijuana grows in the United States with no regard for the age or criminal activities of his customers."
Mr. Emery was handed over to U.S. authorities last Thursday after the federal justice minister ordered his extradition, ending a years-long battle to stay in Canada.
The long-time pot activist, who operates the Cannabis Culture shop in Vancouver, was arrested in the United States in 2005 and indicted by a Seattle grand jury.
He reached a plea bargain last year.
"Marc's very bright, he's very articulate and he's very committed to the cause, but there was no reason for him to have done 10 years when he could have done five," his lawyer, Richard Troberman, said in a telephone interview.
In the plea agreement, Mr. Emery admitted to operating a marijuana seed distribution business called Marc Emery Direct. He made sales via his store, mail and telephone orders throughout the United States, including Washington state. About 75 per cent went to Americans.
He also admitted to selling grow equipment and providing advice on cultivating the drug.
Mr. Emery's business was infiltrated by undercover Drug Enforcement Administration agents between 2004 and 2005, who bought seeds from his store and elsewhere.
He claimed on his website to have made about $3-million a year in sales, having sold more than four million seeds over the years.
Mr. Emery will stay in custody at the SeaTac Federal Detention Centre in Washington until his sentencing on Aug. 27. He'll then pursue serving the term in Canada, Mr. Troberman said.
Under the terms of the deal, Mr. Emery must be sentenced to five years in prison or either side can withdraw. He waves his right to appeal if the judge imposes the specified term.
Two of Emery's co-accused, both Cannabis Culture employees, pleaded guilty to the same charge last year and received probation.
Mr. Troberman said it's unlikely Mr. Emery will continue to fight his cause behind bars. But he believes the prosecution hasn't dealt the blow the U.S. hoped it would.
"Many years ago when Marc was first charged in this, the government made a big deal about it and said this was somehow going to have a major impact on the marijuana business," Mr. Troberman said.
"I think over the years they've realized that's simply not the case, and I don't think that anybody would rationally suggest now that this is going to have any impact whatsoever on the marijuana business."
The Canadian Press