* Max Marambio lives in Chile, sentenced in absentia
* One of several high-profile corruption cases in Cuba (Updates with Marambio quote)
HAVANA, May 5 (Reuters) - A Cuban court has sentenced Chilean businessman Max Marambio, once a close friend of Fidel Castro, to 20 years in prison and a former Cuban food industry minister to 15 years after convicting them in a high-profile corruption case, official media reported on Thursday.
The court sentenced Marambio, 63, in absentia because he lives in Chile and has refused to come to the communist-ruled Caribbean island since the investigation of the case began.
He and former food industry minister Alejandro Roca were convicted in a March trial for bribery and other crimes related to Marambio's business operations in Cuba.
Marambio had a joint venture with the Cuban government known as Rio Zaza that produced fruit juice, milk and other products. It was investigated for financial irregularities.
He was called to appear before Cuban investigators last year but refused to travel from Chile to Cuba. He was tried in absentia with a court-appointed lawyer representing him.
From Chile, Marambio said there were no grounds for the charges brought against him.
"There's a new government in power made up of people with few ethics and scruples. That's all this is," Marambio told local radio. "I'm being persecuted by a bunch of thugs."
The court found the alleged crimes of Marambio and Roca, who left office several years ago, had caused so much damage to the Cuban economy that they deserved a long sentence, Communist Party newspaper Granma said.
The Rio Zaza case was one of several high-profile business corruption cases under investigation in Cuba, where President Raul Castro, who succeeded older brother Fidel Castro in 2008, has ordered a crackdown on graft.
Marambio was the bodyguard of Chilean President Salvador Allende, a Cuban ally, who died in a 1973 coup.
Marambio went into exile in Cuba, where he became friends with Fidel Castro as he built a business empire on the island that extended to other Latin American countries. He eventually returned to Chile.
Marambio said in October he had filed a complaint about Cuba's investigation into his company with an international business tribunal in Paris. (Reporting by Nelson Acosta; Editing by Jeff Franks and Vicki Allen)