By CBS13 Staff

MARYSVILLE (CBS13) — Authorities have now released the cause of death of the man whose body was found in a Marysville recycling center in April.

Ron Lamp’s body was discovered at the Material Recovery Facility along N. Levee Road back on April 26.

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The Yuba County Sheriff’s Office says, based on where Lamp was found, it appeared that the body had been brought in by a cardboard-recycling truck. Exactly when the body arrived – and where it was picked up – is unclear, but investigators believe it arrived at the recycling center sometime during the previous week.

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An autopsy on Lamp has found that his cause of death was “probable asphyxia due to entrapment in a recycling truck,” the sheriff’s office says. A toxicology report also showed that Lamp had been under the influence of a controlled substance.

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Lamp was a resident of Magalia, the sheriff’s office says.