A Florida politician who has run a pro-medical marijuana campaign said Wells Fargo & Co. closed her account over her ties to the industry, adding that the incident was an example of the challenges legal cannabis businesses face from the U.S. financial system.

Nikki Fried, a Democrat running for state agricultural commissioner, said the bank notified her Aug. 3 that it was ending their relationship because of her advocacy for medical marijuana and contributions accepted from industry lobbyists. Her account was initially flagged because of her political platform, according to remarks she posted Monday on Facebook.

Fried said that when Wells Fargo contacted her, she initially thought it was a joke. She said her campaign is moving its accounts to BB&T Corp., which hasn’t yet raised concerns about the marijuana issue.

“It is Wells Fargo’s policy not to knowingly bank or provide services to marijuana businesses or for activities related to those businesses, based on federal laws under which the sale and use of marijuana is illegal even if state laws differ,” Michael H. Gray, a spokesman for San Francisco-based Wells Fargo, said in an emailed statement. He said the bank doesn’t discuss specific customer accounts.

Fried seized on the development to blast businesses and officials who she said were discriminating against a legal industry. While medical marijuana is now allowed in Florida and other states, it remains illegal under federal law. Among other challenges, she said medical marijuana workers can be targeted for armed robbery because financial institutions refuse to work with them, forcing them to run cash businesses.

“At a time when 30 states including Washington, D.C., have legalized medical marijuana and licensed businesses to practice and distribute marijuana to patients and caregivers, access to basic financial stability is virtually impossible for these legal businesses,” Fried said. “Outdated federal laws allow for this sort of discrimination.”