MANILA, Philippines--Malacañang says it welcomed the return of former agriculture undersecretary Jocelyn Bolante as a "positive development" in shedding light on a fertilizer fund scam and appealed to senators to exercise "responsibility, sobriety, and fairness" in investigating the matter.

Bolante, who allegedly funneled P728 million in fertilizer funds to President Gloria Macapagal-Arroyo's campaign kitty in 2004, arrived at Terminal 1 of the Ninoy Aquino International Airport (NAIA) on board Northwest Flight 71 at 10:32 p.m. Tuesday. He was visibly thinner, sported white hair, and was brought to a waiting ambulance in a wheelchair.

"Joc-Joc Bolante's return to the country should be commonly viewed as a positive development," Presidential Adviser on Political Affairs Gabriel Claudio said in a text message, adding: "His expression of willingness to answer all questions and accusations against him on the fertilizer controversy is welcome and reassuring."

Claudio said the Palace was hoping that Bolante's testimony would "serve the ends of truth and justice."

"Malacañang will not interfere with or get in the way of opportunities for Mr. Bolante to be heard in the Senate and other legitimate fora," Claudio said.

"We hope that such inquiries and for a will be undertaken with responsibility, sobriety, and fairness so that the truth can be more effectively served," he said.

The former undersecretary was deported to the Philippines from the United States after his petition for political asylum there was denied.

The Senate Sergeant-at-Arms took custody of Bolante at the airport, but instead of being transferred to the Senate, Bolante was brought to the St. Luke's Medical Center for a medical check-up.

Senate President Manuel Villar had earlier issued a warrant for Bolante's arrest. Bolante had snubbed a Senate inquiry on the fertilizer fund controversy in 2006.