The man arrested at the scene of a fatal stabbing of a 12-year-old boy at a downtown Toronto hotel was a family member, police said.

Details are scarce about the stabbing, which happened Wednesday before 6 a.m. ET at the Cambridge Suites Hotel near the intersection of Richmond Street East and Victoria Street.

No charges have been laid yet and no names have been released, said Toronto police Det. Omar Khan. The family members were guests at the hotel.

"Because of the age of the victim, I can only release very limited information," Khan said. "I can say, however, at this time I do not believe there is any immediate threat to public safety."

Police found the boy in life-threatening condition on the eighth floor of the highrise tower. He later died in hospital.

Khan said several 911 calls were made about the incident, but refused to comment on whether the child was stabbed inside a room at the hotel or in a hallway or other public area.

Hawaiian tourist Edwin Baldelomar, who is staying at the hotel, said police were canvassing the building.

"They asked me, 'Did you hear any commotion?'" he said. "It's a sad story. I just can't believe what happened."

Police are asking for any witnesses to come forward.