MANILA - Relations between the Philippines and Malaysia came under new strain Thursday after Manila reacted furiously to reports a 13-year-old Filipina girl was raped while awaiting deportation.

Last night, President Gloria Arroyo sent a letter to Prime Minister Dr Mahathir Mohamad demanding swift prosecution of the alleged attacker, identified by local reports here only as a policeman assigned to a detention center in Kota Kinabalu.

Philippine Foreign Secretary Lauro Baja said today the government was studying the possibility of filing a complaint with the United Nations Human Rights Commission over the incident.

The strong reaction came despite Malaysia's denial the incident took place, and follows weeks of tension over conditions in deportation camps in the eastern Malaysian state of Sabah.

Bilateral solution

"The chief minister of Sabah and the police authorities there are already aware of the case and are conducting their own investigation," Baja said on local television.

"At the moment, we are stressing a bilateral solution to this issue, but at the same time we are exploring the option of bringing it to a regional forum or to the United Nations," Baja said.

Baja said the Philippines was stressing the urgency of resolving the issue to avoid further damage to bilateral ties, and he stressed both countries were still cooperating on security and trade.

No other details about the girl were released, but press reports quoted social workers as saying she was among 500 deportees who arrived in the southern Philippines aboard a Coastguard vessel on Tuesday.

They were the last batch of deportees to leave Sandakan in Sabah after Kuala Lumpur last week agreed to freeze deportations to allow a team from the Philippines to inspect detention centres.

Thousands of Filipino illegal immigrants have been deported or have left voluntarily for the southern Philippines after Malaysia introduced tough new laws in August against illegal migrants.

Many alleged they were mistreated in Malaysian detention centers, leading the Philippine government last week to file a diplomatic protest.

Swift investigation

The Philippines' Foreign Ministry late yesterday summoned Malaysian ambassador to Manila Taufik Noor to receive another dressing down.

A statement handed to Noor condemned "in the strongest terms" the alleged rape and called for a swift investigation.

Malaysia's crackdown on illegal immigrants, has also sparked protests in Indonesia.

Some 380,000 people, mainly from those two countries, fled Malaysia during a four-month amnesty ahead of the introduction last month of the law which carries harsh punishments for illegal immigrants, including jail terms and caning.