The pending merger of US beer giant Anheuser-Busch and a Belgian company that brews and sells beer in Cuba is thrusting presumptive Republican presidential nominee John McCain into the middle of thorny Cuba-US relations.

McCain's wife, Cindy, owns the third largest Anheuser-Busch distributor in the country - which means she would stand to profit by partnering with a company that is in business with the Cuban government.

McCain is a staunch advocate of the embargo against Cuba, which bars most American companies from doing business in the island nation.

Among the yet-to-be-resolved issues in the $52bn deal is whether Belgian giant InBev - expected to operate under the name Anheuser-Busch-InBev - will continue to market its Cuban line of beer, and what that may mean for US distributors.

Two of McCain's top Florida supporters, Miami representatives Lincoln and Mario Diaz-Balart, assailed the InBev-Anheuser Busch deal earlier this month, saying they are "deeply concerned" that Anheuser-Busch is about to be purchased by a company "with ties to the Cuban dictatorship, a state sponsor of terrorism".

A spokesman for the Diaz-Balarts said last night the two congressmen stand by their statement.

According to financial disclosure statements, Cindy McCain also owns stock in Anheuser-Busch and would stand to make as much as $2m in profit if she sells the shares after the merger.

McCain's campaign did not respond to questions about whether Cindy McCain's distributorship in Arizona, Hensley and Company, would continue to market InBev products after the merger goes through.

The private company, with annual sales estimated at between $150m and $200m, already distributes InBev products, including Stella Artois, Beck's and Lowenbrau.

A longtime McCain supporter said the Arizona senator has maintained a rigid firewall between himself and his wife's business operations, and new owners won't change matters.

"Making a connection between InBev, John McCain and Cuba policy is a ridiculous stretch of the imagination," said Ana Navarro of Miami, who has known McCain for years and serves as a co-chair of his National Hispanic Advisory Council. "First, because John McCain has nothing to do with the operation of his wife's business and secondly, her business has nothing to do with Anheuser-Busch's sale. Does Publix (a grocery store chain) control the decisions of Frito-Lay?"

InBev isn't saying whether or not it will keep what it calls its "modest" Cuban interests.

European countries have no hurdles to doing business in Cuba, and a spokeswoman for InBev said the company "continuously reviews" its commercial activities to ensure compliance with international laws.

Marianne Amssoms, InBev's vice-president of global external communications, said the company's Cuban interests are all handled out of Europe. She said the company's Cuban interests "do not violate US, EU or international law".

She said the business in Cuba is less than half of 1% of InBev's global business.

According to the company's website, its plant in Holguin, in eastern Cuba, employs 570 full-time workers.

A spokesman with the US treasury department, which along with the US state department oversees provisions of the embargo, said the agency could not yet comment on whether the embargo would apply or how the new company would be affected by the embargo law.