Melissa Etheridge, who legally uses marijuana for pain that stems from cancer in her home in California, was arrested for possession of marijuana oil at the Canadian border this summer, a new report says.

According to TMZ, Etheridge was done in by sniffing dogs in August in North Dakota, where she'd been stopped by the U.S. Customs and Border Patrol. Etheridge'd bus had been returning to the United States, but possession is illegal at the point of her reentry.

Etheridge was charged with "possession of a controlled substance" and pleaded not guilty.

The rock star opened up to Yahoo! in April about her relationship with marijuana, which she's used occasionally and recreationally since age 21, but more for medicinal purposes after treatment for breast cancer in 2004.

"I asked many of my friends [who had gone through chemo], 'What's the experience? What are you doing?' And my friend David Crosby, he was the first one who said, 'You know, Melissa, you have to do medicinal marijuana. You have to [try] cannabis. That's the way to do it. It's too hard otherwise,'" she said.

"When I used it as medicine, it became so clear to me that it has been maligned and misunderstood, and I really wanted to help people who are suffering," she added. "I mean, going through chemotherapy is suffering...and cannabis helps so many parts of just that."

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