Malacanang does not see any problem if security forces have been casing opposition Senator Antonio Trillanes IV and other individuals who have been openly calling to overthrow President Rodrigo Duterte.

"It's only proper to case individuals who have been openly advocating the overthrow of a duly elected, democratically elected President," said Presidential Spokesperson Harry Roque in a press briefing.

He said casing is "perfectly legal" as long as there is no violation of the privacy of Trillanes' house.

In a budget hearing at the Senate on Tuesday, Armed Forces of the Philippines chief of staff Carlito Galvez Jr. admitted there were members of the military deployed near the house of Trillanes.

The opposition senator earlier claimed there were military men who were conducting surveillance in his house in Antipolo City.

The surveillance started since Trillanes decided not to go home and remain at the Senate after Duterte issued a proclamation voiding his amnesty. This was to avoid arrest.

Trillanes only returned to his house last Saturday morning after a Makati court deferred the issuance of a warrant of arrest on his coup d'etat case. Celerina Monte/DMS