A former U.S. ambassador to Bolivia was sentenced Friday to 15 years in prison for more than 40 years of spying for Cuba. AFP the report said.

Victor Manuel Rocha pleaded guilty to “acting as an unlawful agent of a foreign government” and defrauding the U.S. government.

Rocha, 73, was arrested in December in what U.S. officials considered “one of the most significant and sustained infiltrations of the U.S. government by foreign agents.”

He was charged with conspiracy to act as an agent of a foreign government and sentenced to 10 years in prison and a $500,000 fine for acting as a foreign agent.

During a court hearing in Miami, Rocha accepted full responsibility and the judge said: “You have turned your back on this country time and time again.”

Rocha is a naturalized U.S. citizen from Colombia and served as ambassador to Bolivia from 2000 to 2002.

The former envoy also served as deputy director of the U.S. Interests Section in Cuba in the 1990s and worked at embassies in the Dominican Republic, Italy, Mexico and Argentina.