MANILA (REUTERS) - The Philippines' fight to end cyber sex trafficking needs other countries to get tougher with sexual predators who pay to watch children being abused over webcam, a Filipina senator said.

Organisations such as the United Nations' children's agency (Unicef) say the Philippines is the epicentre of a growing cyber sex trafficking trade, with many children forced to perform sex acts, abused and raped by relatives in front of a webcam.

The Philippines receives at least 3,000 reports per month from other countries of possible cases of its children being sexually exploited online, said the Department of Justice.

Senator Loren Legarda said the South-east Asian nation must better enforce its anti-trafficking law, which carries the threat of life imprisonment, but there must be global action to stop cybersex trafficking, where victims are sold for sex online.

"Developed countries, from which the demand for online sexual exploitation of children usually originates, must do their part," she told the Thomson Reuters Foundation days after delivering a speech on cyber sex child trafficking to the Senate.

She cited a recent case in Queensland, Australia, where a man was spared jail and fined US$500 (S$656.95) after being convicted of receiving explicit images of two girls from a Filipina mother.

"This calls for amending the lenient sentences that their laws mete upon those who prey on Filipino children... raise the penalties to lower the demand," added the three-time senator and first woman to be elected head of the Philippines' Upper House.

At least 400,000 people in the country - or one in 250 - are estimated to be trapped in modern slavery, according to the 2016 Global Slavery Index by the Walk Free Foundation.

The Philippines is considered a regional hotspot for trafficking - from domestic workers who are exploited and enslaved overseas to forced prostitution in the nation's booming sex industry and now to cyber sex trafficking.

"We get a lot of help from the likes of Australia, Britain, Germany, Norway and the United States when it comes to tackling the online sexual exploitation of children... but we need more," said Ms Juvy Manwong, assistant secretary at the department.

"It is disheartening to see soft punishments against abusers in other countries," she told the Thomson Reuters Foundation.

Ms Legarda said the Philippines must also raise awareness of the crime and the country's anti-trafficking law - to deter abusers and encourage the public to report cases - and teach children how to better protect themselves offline and online.

Police, prosecutors, charities, and government and aviation officials in Angeles - one of the country's major trafficking hubs - last week joined forces in a city-wide drive to identify traffickers, boost victim support and keep people from harm.

"The illegal trade is a complex web - battling it requires a concerted effort from all sectors of society," Ms Legarda added.