Australian taxpayers have forked out about $500,000 for the legal costs of alleged paedophile Peter Scully, who is accused of child murder, torture, trafficking and rape in the Philippines.

The federal government is considering tightening access to the Serious Overseas Criminal Matters Scheme following scrutiny of Scully using it since his arrest in 2015.

Attorney-General Christian Porter has called on his department to review the scheme, available to Australians facing the death penalty or more than 20 years' jail overseas, and consider if persons accused of sexual offences should be barred.

Peter Scully has been accused of some of the most vile child exploitation charges ever investigated in the Philippines. Credit:Kate Geraghty

“I had already asked my department for information on the scheme, including this particular case, with a view to considering changes to the scheme, so that persons in circumstances similar to Mr Scully or those with histories of sexual offending and relevant convictions would no longer be eligible,” he said.