Philip Ruddock has flagged his review into legal protections for religious freedom in the wake of marriage equality may seek a deadline extension.

The former immigration minister and a panel which includes Australian Human Rights Commission President Rosalind Croucher have been tasked with reviewing the issue following the passage of same-sex marriage laws on December 7.

The panel met in Sydney on Wednesday for the first time.

Mr Ruddock says the panel has received more than 100 public submissions so far and has extended the deadline to mid-February.

All submissions will be published unless they present legal issues such as defamation.

The panel is due to report back by the end of March, but Mr Ruddock flagged on Thursday it may need more time.

He says he is open-minded about the complex issues the panel will consider.

On one hand, he said people should be able to practice their religion as they see it, but he also recognised that many of the values of religions undergo a modernisation.

"You can find endorsement of the death penalty in parts of the Bible, and that's not something I support," Mr Ruddock told ABC Radio.