Former Australian soldier Warren Rodwell, released at the weekend after 15 months in clutches of Islamic terrorists, is likely to remain in Manila for at least another week as he recuperates.

Mr Rodwell appeared emaciated and very weak when he arrived in the Philippine capital on Monday afternoon, where he was met by his Australian brother and sister.

He will return to Australia early next month.

But before he does, the 54-year-old is expected to provide crucial information to Philippine authorities to aid in the hunt for the terrorists who had held him prisoner in various jungle hideouts after they kidnapped him from his home on the southern island of Mindanao in December 2011.

The head of the Philippine police's anti-kidnapping unit, Renato Gumban, said Mr Rodwell would remain in Manila for up to two weeks to rest and undergo medical treatment.

"We will wait for him to fully recover before we subject him to an intelligence debriefing," Senior Superintendent Gumban said, according to Fairfax Media.

Mr Rodwell's kidnappers - members of the al-Qaeda linked Abu Sayyaf - had initially threatened to kill him unless a $US2 million ($A1.93 million) ransom was paid.

In the end, they settled for just under $A94,000 after a deal was brokered by the vice-governor of the southern Philippine province of Basilan, Al-Rasheed Sakalahul.

Mr Sakalahul also flew to Manila on Monday, where it was expected he would meet with Mr Rodwell's Australian relatives who wanted to personally thank him for his efforts.

The ransom was paid for by money raised with the sale of property, including a house, Mr Rodwell's Filipino wife, Miraflor Gutang, has said.