The dismembered remains of the 33-year-old were found after passers-by spotted a suitcase in the Canal last weekend
Gardai investigating the murder of Kenneth O'Brien are trying to track his last movements.
They are also continuing searches of farmland and outbuildings in Co Kildare, near where his body was found in the Grand Canal.
Over 200 lines of inquiry are now open after the 33-year-old's dismembered body was found in a suitcase in the Canal at Ardclough on Saturday.
A detailed description of the suitcase is due to be released.
Gardaí say that they are still trying to find out where Mr O'Brien was killed.
The Sunday World's Investigations Editor Nicola Tallant says gardaí are checking CCTV to find out his last journeys.
Speaking to Newstalk Breakfast, Nicola explained, "they're going to be looking at CCTV to try and establish was he picked up, was he given a lift, did he get on the Luas.
"Certainly whoever he last saw, if he was given a lift, hasn't come forward in the investigation, so that would be significant," she added.