At least two men were involved in the assault of 51-year-old Frank McGreevy, at his flat in Ross Street, yesterday evening.
The victim, a former Republican prisoner, is on a life support machine at Belfast's Royal Victoria Hospital.
Detective Superintendent Jeff Smyth said the assault scene was as bad as any he had seen.
He confirmed that a pickaxe handle was recovered and that the flat had been ransacked.
Local Sinn Fein Councillor Tom Hartley says residents of the area had phoned the police about some of the parties involved in the incident and they were unhappy about the slow response.
There is an ongoing problem of street crime and anti-social behaviour in Belfast.
Last September in a nearby area of the city a local greengrocer died after he was stabbed with a screwdriver.
