Chief Superintendent Rosalio Magsino, head of the PNP security and protection office, said close-in personnel for Estrada was increased from six to 11 men.
Intelligence reports had it that some groups were to take advantage of the small number of policemen securing the former president who is confined at the state-run Veterans Memorial Medical Center (VMMC) in Quezon City, along with son Jinggoy.
Both are facing the capital offense of plunder with six other co-accused.
Apart from Task Force Veterans and Task Force Sandigan, six policemen are on security detail at the VMMC.
Magsino heads Task Force Veterans while Task Force Sandigan is under the supervision of Metro Manila police chief Director Edgar Aglipay.
Magsino said the additional policemen will be posted in strategic areas while the Estradas are being transported to the anti-graft court Sandiganbayan for the trial of the plunder case.
Magsino said the family-owned bulletproof Toyota Lexus will be used to bring the Estradas to the court and back to the VMMC.
Superintendent Marcos Lumanog Flores, head of the police escorts, said assassins might attack while the Estradas are being transported.
Meanwhile, the opposition Partido ng Masang Pilipino (PMP) assailed the Supreme Court (SC) for allowing the creation of a special court to hear the cases against the former president.
PMP spokesman Crispin Remulla described the special court as a "sham kangaroo court created not to hear and give fair judgment but present a pre-arranged ruling."
In a statement, Remulla indicated that the high tribunal abused its authority granted by the Constitution mandating that cases should be raffled off and not be just assigned to any court.
The SC, he said, practically abandoned its moral and social obligations as it has metamorphosed into "judge, jury and executioner" of Estrada when it is supposed to act as final arbiter of the law.
Remulla said the special court was intended to ensure a conviction of Estrada and his co-accused "after the prosecution bungled the case" against them.
Also, Remulla said the SC decision was reminiscent of martial law when special courts called special military tribunals were created to persecute perceived enemies of the State under the mantle of legal proceedings.