A growing number of British Columbians are getting busted at the U.S. border for pot possession because of conflicting marijuana laws, an American immigration lawyer says.

Since Washington State legalized possession of small amounts of marijuana last November, confused Canadians have been banned from the U.S. for attempting to bring the drug over the border, Blaine, Wash. lawyer Len Saunders said.

“If you get stopped at the port of entry either with a small amount of marijuana or admit to possessing it in the past or using it, you are deemed inadmissible to the U.S.,” Saunders said.

That’s because though the laws have changed in Washington, possession or even past use of marijuana is still considered illegal at the federal level.

“If they catch you with marijuana, they can’t charge you because Washington State will not prosecute you,” Saunders said. “It’s a catch-22: you're deemed inadmissible for something the state’s not going to prosecute you for.”

The confusion has had Saunders’ phone ringing off the hook not only from B.C. residents trying to bring pot across the border, but also from people with decades-old charges.

“I’m getting more calls than before; people trying to clarify what you can and can’t do,” he said. “They’re now calling me asking if they’re still inadmissible because Washington State allows it, so there’s confusion if you have a past conviction.”

Brian Fowler was caught with a small amount of pot at a B.C.-Washington border crossing in September last year.

He paid a fine and thought that would be the end of it, but he realized things got worse when he returned to the border.

“The judge told me after the fine I’d be okay to go, I’d have no problem at the border and everything should be fine,” he said. “But when I got to the border it wasn’t the case.”

The Surrey man found he’d been banned from entering the U.S.

“The border said ‘no, you need a waiver,’ so I had to get a waiver,” he said. “All I can do now is wait for the waiver so there’s no possibility of going down now.”

American border authorities say that anyone who’s been barred from the country needs a re-entry waiver approved by the government – a process that can take several months and costs hundreds of dollars.

Saunders said there hasn’t been much cooperation on the law between federal and state prosecutors so far, and that since Washington changed its pot laws, border officials have become even stricter.

“They may have even become more tough because they’re trying to emphasize that illegal drugs is not okay in the U.S. even though it is okay in Washington State,” he said.

With a report from CTV British Columbia’s Scott Roberts