Montenegro has defended its decision to allow an island fortress and wartime concentration camp to be transformed into a luxury resort, a move that has sparked anger among relatives of its former prisoners. Situated on Mamula island in the Adriatic sea in the popular Bay of Kotor, the 19th century fort was run by fascist Italian forces during World War II as a concentration camp where dozens of inmates are believed to have died. Now the Balkan country has granted a 49-year lease to Swiss-Egyptian company Orascom to invest 15 million euros ($16 million) to build a high-end hotel with a spa and marina jetty. "We were facing two options: to leave the site to fall into ruin or find investors who would be willing to restore it and make it accessible to visitors," Olivera Brajovic, head of the national directorate for tourism development, told AFP late Friday. Relatives of some of those detained at Mamula during the war have however come together to oppose the project, which they say is inappropriate given the island's dark past. "To build a luxury hotel dedicated to entertainment at this place where so many people perished and suffered is a blatant example of lack of seriousness towards history," campaigner Olivera Doklestic told AFP. The 54-year-old woman, whose grandfather, father and uncle were imprisoned at Mamula, said the fortress should be renovated and opened to visitors as a historic site. "No concentration camp in the world has been transformed into a hotel," she said. According to the local war veterans' association, Mamula had more than 2000 prisoners, 80 of whom were executed while 50 others died from hunger amid the grim conditions. Brajovic said plans for the conversion included a memorial room to former inmates. While prisoners' relatives oppose the hotel plan for Mamula, Montenegrin PR agency Magna, which represents Orascom, said the local war veterans' group had given approval for the project, which includes plans to conserve the fortress. According to the World Travel and Tourism Council, Montenegro is ranked third in the world for its tourism industry's long-term growth forecast.