Jewish-American contractor Alan Gross has been sentenced to 15 years in prison in Cuba for helping Cuban Jews connect to the Internet. Gross was convicted of “acts against the independence and territorial integrity of the state.”

Gross, 61, has already been in prison for 15 months. His attorneys said they would look into the possibility of appeal. His family has appealed for his release on humanitarian grounds, due to the fact that both his mother and his daughter are suffering from cancer, and that Gross himself has become ill in prison. Jewish leaders have called for his release as well.

He was in Cuba on behalf of Development Alternatives Incorporated, which in turn was hired by the U.S. government to carry out “democracy building efforts” in Cuba. Cuban authorities termed the project was “subversive” and accused its organizers of aiming to undermine the government.

Cuban sources reported that Gross said he had been “used and manipulated” by DAI, a report that could not be confirmed due to the lack of independent media in the country.

U.S. officials denounced the verdict, with Secretary of State Hillary Clinton saying that Gross has been “unjustly jailed for far too long.” Gross “needs to be able to leave Cuba and return home,” she said.

National Security Council spokesman Tommy Vietor called for Gross' immediate release, accusing the Cuban court of “injustice.”