Sara De Boer/Retna Ltd. 1 / 3
Sara De Boer/Retna Ltd. 1 / 3

Actor Matthew Underwood has pleaded not guilty following his arrest for violating his probation earlier this month.

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The former star of Nickelodeon's popular "Zoey 101" series was picked up by police outside Cloud 9 -- the venue he co-owns in Port St. Lucie, Fla., -- on Nov. 7.

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It came just months after the 22-year-old actor was arrested in April on suspicion of marijuana possession and contributing to the delinquency of a minor. He pleaded no contest and was sentenced to 12 months of probation.

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TMZ.com reports that Underwood failed a drug test and had not completed a substance abuse program -- and he has now pleaded not guilty to violating his probation.