Manila - Former Philippine president Joseph Estrada is facing an investigation for allegedly displaying in public a toy machine gun, police said Wednesday.

Police Director General Jesus Versoza said Estrada might be charged for violation of a 1982 edict of former dictator Ferdinand Marcos, which prohibits civilians from displaying real or fake high-powered firearms.

"I think there are some executive orders that are prohibiting the use of toy guns and displaying them in public," Versoza said.

Police investigators said the incident occurred two weeks ago in Carmen town in Cebu province, 585 kilometres south of Manila, during a motorcade in which the former leader was riding a military jeep with a replica of a 50-calibre machine gun.

Opposition leader Jejomar Binay, the mayor of Makati City, was riding in the same military jeep with Estrada and could also face the same charge, Versoza said.

Estrada was convicted of plunder and sentenced to life imprisonment by an anti-graft court in 2007 but was pardoned by President Gloria Macapagal Arroyo a few months later in an apparent bid to woo the supporters of the charismatic former leader.

Estrada, however, ignored the reconciliation call of scandal-tainted Arroyo and has continued to lead the opposition against her administration.

"This looks very much like another case of harassment by the administration," Estrada spokeswoman Margaux Salcedo said.

The Marcos edict, issued in July 1982, which remains in force until today, penalizes the sale, use and display of gun replicas. (dpa)