The 60-year-old man who was maimed by a parcel bomb last week remains in critical condition despite a slight improvement.

Philip Cini is still sedated, which means he cannot yet speak to investigators who are counting on his input to try to solve the case, police sources said.

Mr Cini has been in intensive care at Mater Dei Hospital since the explosion on December 22.

Investigations have hinged on forensic evidence but the police are hoping that Mr Cini's recovery would help shed light on the motive behind the case and possibly lead them to the perpetrator. Police sources said a package was delivered to Mr Cini's Qormi home on the morning of the incident. Mr Cini's wife, Doris, found it behind the door and took it upstairs to the kitchen.

When Mr Cini arrived at about 1.30 p.m., he unwrapped the parcel - addressed "To Philip from Doris" - and saw that inside there was a hollowed out book that acted as a casing for a contraption with a battery pack and switch. The parcel then blew up, the sources said.

Mr Cini lost his left hand and had to undergo an operation because of serious injuries to the left side of his torso.

His wife, who had warned him not to open the parcel, and their eight-year-old grandson escaped uninjured despite standing close to him.

Investigations have excluded the possibility that the parcel was delivered by postal services.