Police and fire service sources said that a 14-year-old girl was taken to hospital suffering from the effects of intoxication after inhaling the leaking gas.
She was taken to Son Llatzer Hospital in Palma where she was said to have been recovering well yesterday afternoon.
According to the police, the leak was reported late on Friday night.
The decision to evacuate the hotel, in calle Mossen Antoni Alcover, was taken at around midnight and the 400-plus guests were accommodated in surrounding hotels in a complicated operation.
Yesterday morning, the establishment remained sealed off and under police guard while guests were only allowed to return to their rooms to collect their belongings accompanied by members of the local police.
Yesterday afternoon, a full investigation into the cause of the gas leak was under way.
Fortunately, no one else needed medical attention.