A Catholic nun has been ordered to leave the Philippines within 30 days after the country's President Rodrigo Duterte personally complained about her participation in protest rallies.

Patricia Anne Fox, a 71-year-old superior of the Notre Dame de Sion in the Philippines, was detained for a day last week after Duterte ordered her investigation for 'disorderly conduct'.

The immigration department said she had engaged in activities not allowed under the terms of her visa.

It did not elaborate but Duterte had accused her of violating Philippine sovereignty with criticism of the government. A presidential spokesman recently showed journalists photos of Fox speaking at a rally by farmers and workers.

The Philippines' government under Duterte has lurched sharply to the right and has been accused of many breaches of human rights, with particular attention focused on extra-judicial killings by police and security forces.

In a statement posted on her social media page Fox said she was 'very sad that the decision at present is that I leave the Philippines'.

She said she had been in the country since 1990, spending most of her time with rural people. 'It was through them that I came to learn some of the basic issues which caused their poverty: lack of their own lands, control of markets, dependence on pesticides,' she said. 'I stayed with tribal people and learnt how the mountains are their supermarkets and pharmacies, how they were excited to have their own schools which taught sustainable agriculture but also preserved their culture. But also about how large mining and logging corporations as well as plantations were threatening the life and livelihood of these rural people.'

She continued: 'As a Christian, believing that our mission is to bring God's Kingdom to the here and now, I couldn't help but to get involved both with projects, such as training in organic farming, to uplift the livelihood of the farmers, but also to advocate with them for their rights to land, livelihood, peace, justice and security, all universal human rights which the church sees as integral to her mission.

'It seems this is what has brought me into conflict with the Philippine Government. I am still hoping for a chance to explain how I see my mission as a religious sister and maybe the decision can be reconsidered.'

Additional reporting by Reuters