Investigators believe a woman of 44 accidentally fell down the stairs of her Kalkara home on Saturday afternoon but have not ruled anything out yet.
Mary Tabone was found by the police lying face down in a pool of blood at about 5 p.m. She was taken to Mater Dei Hospital in a critical condition.
The police were alerted after a neighbour peeked through her letterbox and saw her on the floor, but they found no sign of a break-in, sources said.