Companies hiring new employees should ask prospective hires if they have any current or past connection to the marijuana industry that could put them in the crosshairs of US border officials, he said.
According to the Politico article, USA border officials allow people admitting to past illegal drug use a chance to "voluntary withdraw" from the border or face what's called "expedited removal".
He also said that investors in the industry could also face a ban.
"Working or having involvement in the legal marijuana industry in U.S. states where it is deemed legal or Canada may affect an individual's admissibility to the U.S.", Mike Niezgoda, a spokesman at the U.S. Customs and Border Protection office in Buffalo, said in an email.
"Of course there's always going to be a concern, but the reality is, I can only tell the truth", he said.
People who have received bans still have the possibility of applying for a waiver from US Customs and Border Protection (CBP).
Canadian Prime Minister Justin Trudeau said that marijuana will be legal across the country starting October 17. "We don't recognize that as a legal business". Under the policy, U.S. officials are to bar entry to Canadians who acknowledge having consumed marijuana at any time in their past, as well as those who are either employed or invested in legal cannabis enterprises.
He added that rather than lie at the border it is better to not respond to the questions.More news: Josh Gordon Released by Cleveland Browns
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Len Saunders, an immigration lawyer in the state of Washington who represents people dealing with cannabis-related issues, said he did not think that an average investor in cannabis stock would be barred from the U.S. Only people "more actively involved in managing their assets", such as Znaimer, or employees of cannabis-linked venture capital firms, are likely to face such a proscription.
Although Owen didn't specify any minimum level of investment, he signaled that the focus was more on those bringing the sector to the US, which could have implications for the burgeoning sector.
Canadian Public Safety Minister Ralph Goodale has often said he's working with USA law enforcement to clarify the changes and make sure the border remains smooth.
So what to do when you want to cross the border?
"Despite one-in-eight Canadians using cannabis today, 400,000 people move between our two countries every day nearly entirely without incident", Goodale spokesman Scott Bardsley said by email.
Despite that Canada will have legal cannabis nationwide in a month, and that a majority of states have legalized cannabis to some extent, the plant remains illegal at the federal level.
Cars from Canada line up to cross into the U.S.at Blaine, Wash.
"If you work for the industry, that is grounds for inadmissibility", Owen told Politico.