A 31-year-old Moroccan man was found dead following an argument in Spinola Gardens on Sunday morning, with police later arresting a 27-year-old Polish man in St George's Bay.

Police were informed at around 6.30am that a man who appeared to be lifeless was in Spinola Gardens, with district police officers immediately going to the scene and confirming the report.

Preliminary investigations showed that an argument had allegedly taken place a short while earlier between the 31-year-old victim and the 27-year-old alleged aggressor, who subsequently left the scene.

Following an intensive search and after obtaining footage which helped identify him, police arrested the alleged aggressor in the St George's Bay area.

Police spokesperson Brandon Pisani told journalists at the scene that officers from the Rapid Intervention Unit carried out the arrest.

The alleged aggressor is currently in police custody and is being interrogated.

The victim was taken to the mortuary, where an autopsy was carried out. TVMnews reported that footage obtained from nearby security cameras appears to show the alleged aggressor punching the victim, who then fell and died from the impact. A wound to the back of the victim's head was clearly visible from behind the police cordon. Reports also identified the victim as Abdellatif Oumakhlouf, while the alleged aggressor is boxer Sebastian Malinowski.

Asked how police identified the alleged aggressor, Pisani said officers obtained CCTV footage and began searching the surrounding areas of St Julian's.

The man was initially identified based on what he was wearing, while police also spoke to a number of witnesses as part of their investigation.

Police believe the argument took place sometime between around 5.30am and 7.30am on Sunday, when fewer people would have been in the area.

Asked whether the victim and the alleged aggressor knew each other, Pisani said that, at this stage, there does not appear to have been any relationship between them.

The suspected victim lives in Malta, while the suspect was visiting and was due to leave the islands on Monday. Police said that no weapons were found, and the victim was found with a deep cut at the back of his head.

Magistrate Joe Mifsud was informed of the case and opened an inquiry, appointing several experts to assist.

Investigations by the district police and the Major Crimes Unit are ongoing.

This is the second murder in the space of a week and the third this year.