A 30-year-old man was found dead at the foot of a bastion in Valletta on Monday evening, the police said.
The man, who was from Birkirkara, is believed to have fallen from Hastings garden, which lies above the ditch.
In a statement on Tuesday, the police said that he was found dead in the ditch at around 6.15pm on Monday evening.
Magistrate Elaine Mercieca is leading a magisterial inquiry into the case.
Just last month, police said that they would be investigating four people caught on camera taunting a man who stood above the ditch, contemplating dying by suicide.