The 'phallic' ceramic monument at Luqa (near the former Mambra) had its top part damaged by vandals over the weekend.
It is not known how the monument was damaged, but its top part has been shattered.
The monument was produced by Paul Vella Critien and is officially known as the Colonna Mediterranea.
Mayor John Schembri said he condemned all forms of vandalism. Without going into the artistic merits of the work, he said that the monument was imposed on Luqa by the central government without consultation. The council had subsequently protested that its location was unsuitable.
"We had argued that the site was better suited for a monument to a person linked to Luqa or to civil aviation," Mr Schembri said.
He did not know whether the monument would be repaired since it did not fall within the council's responsibility.
The Resources Ministry said in the afternoon that it has requested a report about the damage from Mr Vella Critien.