According to the police, the woman was threatened with a cigarette lighter resembling a pistol by the accused.
In her complaint lodged with the police yesterday, the woman said four men, all in an inebriated condition, entered her room in the guest house on the intervening night of August 15 and 16 and threatened her, Banjara Hills police station inspector K Srinivas said.
"She stated that one of the men, in in his mid-30s, forcibly took her to his adjacent room and sexually assaulted her," he said.
Inspector Srinivas said the woman had come to Hyderabad along with another woman and a man to visit various tourist spots in the city, and all of them were staying in two rooms at the guest house.
Police have registered a case on the charges of rape and under other sections of the IPC.
"No one has been arrested so far. We are investigating the case," the officer added.
Further probe is on.