MANILA (Updated) -- Transportation Secretary Manuel Roxas II ordered Wednesday a thorough investigation on a light plane crash in Masbate City, which killed Local Government Secretary Jesse Robredo and the two pilots.

Roxas asked Civil Aviation Authority of the Philippines (CAAP) Director General William Hotchkiss III to conduct the probe involving Aviatour Air, the operator of the Piper Seneca plane that crashed off Masbate on Saturday afternoon.

CAAP formed a composite team to serve as the Aircraft Accident Investigation and Inquiry Board, headed by Captain Amado Soliman, an aviation industry expert in flight safety for over four decades; Captain Ramon Flores; and Captain Elmer Pena.

Hotchkiss said a suspension order has been issued by CAAP grounding all aircraft used by Aviatour Air pending result of the full-blown investigation.

He added that CAAP was among the government agencies that readily mobilized their unit last Sunday, immediately sending the CAAP Go Team headed by Soliman together with Captain Lorenzo Gumba and Engineer Reyner Bucalinao to Masbate right after the plane crash accident to gather all information and facts that could shed light to the accident.

CAAP provided the coordinates of the possible location where the plane crashed within one nautical mile radius, an almost accurate grid where the plane was found later, he said.

Hotchkiss said CAAP will keep the plane wreckage at Masbate airport under tight security.

"This will be thoroughly examined by the CAAP composite team to gather accurate data on the real cause of the plane crash last Saturday," he said.

Robredo and two pilots died when the twin-engine Piper Seneca plane carrying them en route to Naga City from Cebu City crashed off Masbate after supposedly encountering engine failure.

The wreckage of the ill-fated plane, as well as the remains of Robredo and the two pilots, was found on Tuesday morning, three days after the crash, some 800 meters from Masbate shoreline at a depth of 150 meters.

Robredo's body was retrieved on the same day, while the body of the pilot Captain Jessup Bahinting was retrieved late Wednesday afternoon. Authorities were still trying to extricate the remains of Nepalese flight student Kshitiz Chand.

Robredo was in Cebu last Saturday to represent President Benigno Aquino III in the ground-breaking of the new Philippine National Police Regional Training Center in Consolacion town.

Presidential spokesperson Edwin Lacierda explained that the decision for Robredo to represent the President during the event has been made in July.

"I'm part of the Appointments Committee and as early as July, Secretary Robredo has already accepted the invitation to speak in Cebu," he said.

"So any insinuation that it was a last minute decision by the President to ask Secretary Robredo to speak on his behalf is entirely not true and it is entirely malicious," he added.

Lacierda said the President continue to mourn the death of Robredo, whom he considers as close friend.

Aquino has ordered to render a state funeral for Robredo, who served as Naga City mayor for several six terms before he was appointed to the DILG. (SDR/Jill Beltran/Sunnex)