Admitting to marijuana use can cause complications at the U.S. border, no matter who you are.

That's the lesson from immigration experts as Olympic snowboarding champion Ross Rebagliati battles an ongoing ban on travelling to Canada's southern neighbour.

Rebagliati, an open pot user who runs a dispensary called Ross' Gold in Kelowna, said he was last denied entry around four years ago because of his well-documented relationship with marijuana.

"They turned me around with my six-month-old baby and my wife and my dog," he told CTV News.

The Olympian said they were trying to head down for a visit with his mother, who lives in California, over the winter. Rebagliati had been sent back before, but the family decided to chance it anyway.

"I had a feeling before I went down that there could be some complications," he said. "[But] being that I don't have a record and that it's just my association to cannabis I felt like we'd have a good shot of getting through."

His case goes to show that it doesn't matter if you're famous, border agents can and will send you packing if they have reason to believe you've ever used illicit drugs, according to immigration lawyer Len Saunders.

"I think it's ridiculous," he said.

It doesn't matter whether the drug use resulted in a criminal conviction, and it certainly doesn't matter that 26 states and the District of Columbia have already legalized marijuana in one form or another.

"Admitting to using marijuana is admitting to using a controlled substance," said Saunders, who works in Blaine, Wash. "It's illegal federally."

There is a workaround, however. People who have been denied entry for drug use can purchase a waiver for US$585, roughly the equivalent of C$800. Unfortunately, they are only good for a maximum of five years.

"[Rebagliati] has an excellent chance of getting a five-year waiver, but the problem is he'll have to renew it every five years again and again for the rest of his life, unless they change U.S. federal laws," Saunders said.

The waiver can be cancelled at any time should the holder admit to continued marijuana use, the lawyer added.

"I've seen cases where someone has a waiver and is asked if they still smoke marijuana, and if they admit to that that waiver will be revoked and they'll have to start from scratch," Saunders said.

Rebagliati's history with marijuana is well-documented; after winning the giant slalom event at the 1998 Nagano Games, he tested positive for pot and was temporarily stripped of his medal.

His gold was eventually returned because marijuana wasn't then on the list of banned anti-doping drugs.

Rebagliati later admitted to smoking marijuana on the Tonight Show with Jay Leno, despite insisting his positive test at the Olympics was the result of second-hand smoke. He’s been vocal about his drug use in several other media interviews since.

With a report from CTV Vancouver's Mi-Jung Lee