(CNN) -- The man once known as Canada's "prince of pot" is now a federal inmate in the U.S. system after a judge in Washington sentenced him Friday to five years in prison. Marijuana activist Marc Emery pleaded guilty in May in U.S. District Court in Seattle, Washington, to a single count of conspiracy to manufacture marijuana after an 18-month investigation into the seed-selling business Emery operated from his head shop in Vancouver, British Columbia. By imposing the five-year sentence, which includes four years of supervised probation, U.S. District Judge Ricardo S. Martinez honored a plea deal that Emery, 52, entered into with U.S. authorities to avoid a lengthier sentence.
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Marijuana activist Marc Emery sentenced for selling marijuana seeds to U.S. customers
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In plea deal with federal prosecutors, Emery admitted to operating seed-selling business
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Emery's lawyer, supporters, claim his prosecution was politically motivated
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"I regret not choosing other methods -- legal ones -- to achieve my goals," Emery says
By his own account, he has been arrested at least a dozen times since 1995 related to his activism, and @placeholder police have raided his shop several times since it opened in 1994.