A 73-year-old man was arrested by the police late on Saturday in connection with a shooting at Wied Ħażrum on Friday.
He is expected to be charged on Sunday afternoon.
In the shooting, Noel Ciantar, a 49-year-old man who has battled NGOs, private landowners and government entities to protect his property rights, was shot in the back with a shotgun.
The aggressor fled the scene and a search for him was undertaken by the police.
His condition was initially serious but he has now been moved out of the Intensive Therapy Unit, the police said.
They also said the suspect is currently at the police lock-up where he was interrogated as investigations continued.