Image copyright EPA Image caption Patricia Fox has been in the Philippines for 28 years

A 71-year-old Australian nun says she will appeal against a decision to expel her from the Philippines for alleged political activity.

Sister Patricia Fox told the BBC she found out she had 30 days to leave the country from the media.

She admitted she had met political prisoners in Mindanao, an island in the south currently under martial law.

But Sister Fox, who's been in the country for 28 years, denies any wrongdoing.

"I woke up and I had messages from media people and one that's a friend of mine... who said the Bureau of Immigration had released a press release in the morning saying that my missionary visa had been cancelled," she told the BBC's Howard Johnson in Manila.

"I was given a temporary visitor's visa for 30 days, and I had to be out of the country within 30 days."

Image copyright Reuters Image caption Supporters lobbied for her release last week

Last week, President Rodrigo Duterte said remarks made by Sister Fox criticising the government had constituted a violation of sovereignty.

He said he personally authorised the Bureau of Immigration to investigate her case because of alleged political activity that breached the terms of her visa.

She was detained overnight last week for "disorderly conduct" but released without charge.

The nun admits to visiting political prisoners on Mindanao, and fasting and praying for their release.

"It's political if you like - the plight of the political prisoners, the plight of the farmers - but it's not partisan political. I haven't been bad-mouthing the president."

Sister Fox said she had been part of a fact-finding mission to Mindanao to investigate reports of human rights abuses.

"The government was denying there were any human rights abuses, so we actually went to interview people who were victims, or their families were victims, and to find out if there are human rights violations and to document them."

There has been growing international pressure on Mr Duterte over human rights, particularly over his country's war on drugs, which has caused the deaths of thousands.

Sister Fox said this was the first time she had had "a run-in" with immigration officials: "I've never had any problems renewing my visa before."

She also says she has not been given a chance to explain her side of the story.

"I would ask that everyone be given due process - whether it's myself, a political prisoner, a farmer. There should be due process, democratic processes that are followed."