All of an estimated 40,000 Rohingya Muslims living in India are illegal immigrants, even those registered with the UN refugee agency, and the government aims to deport them, a senior government official has told Reuters.

Junior interior minister Kiren Rijiju told parliament last week the central government had directed state authorities to identify and deport illegal immigrants including Rohingya, who face persecution in Buddhist-majority Burma.

The United Nations High Commissioner for Refugees (UNHCR) has issued identity cards to about 16,500 Rohingya in India that it says help them “prevent harassment, arbitrary arrests, detention and deportation”.

But Mr Rijiju, a high-profile minister in Prime Minister Narendra Modi’s Hindu nationalist government, said in an interview that the UNHCR registration was irrelevant.

“They are doing it, we can’t stop them from registering. But we are not signatory to the accord on refugees,” he said.

“As far as we are concerned they are all illegal immigrants. They have no basis to live here. Anybody who is an illegal migrant will be deported.”

The UNHCR’s India office said on Monday the principle of non-refoulement or not sending back refugees to a place where they face danger was considered part of customary international law and binding on all states whether they have signed the Refugee Convention or not.

The office said it had not received any official word about a plan to deport Rohingya refugees, and had not got any reports deportations were taking place.

The treatment of the roughly one million Rohingya in Burma has emerged as its most contentious human rights issue as it makes a transition from decades of harsh military rule.

The Rohingya are denied citizenship in Burma and classified as illegal immigrants, despite claiming roots there that go back centuries, with communities marginalised and occasionally subjected to communal violence.

Hundreds of thousands of Rohingya have fled from Burma, with many taking refuge in Bangladesh, and some then crossing a porous border into Hindu-majority India.

Many have also headed to South East Asia, often on rickety boats run by people-smuggling gangs.

Rohingya are generally vilified in India and over the past few months, there has been a string of anti-Rohingya protests.

​Mr Rijiju declined to comment on the deportation process, even as some human rights activists question the practicality of rounding up and expelling thousands of people scattered across the country.

“There’s a procedure, there is a rule of law,” Mr Rijiju said.

“We can’t throw them out just like that. We can’t dump them in the Bay of Bengal.”

India said last Friday it was in talks with Bangladesh and Burma about the deportation plan.

But deportation is likely to be difficult, given Burma’s position that all Rohingya need to be scrutinised before they can be allowed back in as citizens.

Burma officials were not immediately available for comment.

Rohingya mothers face persecution Show all 10 1 /10 Rohingya mothers face persecution Rohingya mothers face persecution Ramida Begum holds her 10-day-old daughter in their shelter in Kutupalang, an unregistered refugee camp in Cox's Bazar, Bangladesh. 'The military caught my husband and burnt our house down a week before I left Myanmar. Since then I don't know whether my husband is dead or alive' Reuters Rohingya mothers face persecution Minara Begum sits inside the shelter, cradling her one-month-old son Ayub. Minara fled to Bangladesh from Nasha Phuru village in Myanmar with her husband and mother-in-law. 'My child doesn't get enough breast milk as I don't eat enough nutritious food. I have to buy milk powder from local market though it's not very good for my son' Reuters Rohingya mothers face persecution Amina, pictured with her 16-day-old daughter Sumaiyin, is in a refugee camp Balukhali that neighbours Ramida and Minara's. 'One and a half months ago the military came to our village and kept firing their guns. I ran away with my neighbours to save our lives. You see us alive here only because the God was so kind. They caught my uncle and my younger brother and we don't know whether they are dead or alive' Reuters Rohingya mothers face persecution Fatema sits beside her one-day-old daughter Aasma in Kutupalang. Fatema fled to Bangladesh from Jambuinna village in Myanmar two months ago after her house was burnt down by the military. She crossed Naf River by boat during the night. 'Our situation is better than many other refugees as my husband Mohammad Alom works here as a day labourer. Many of the new refugees have no work here, so they have to rely on relief' Reuters Rohingya mothers face persecution Jamalida cradles her two-month-old daughter Shahida. Jamalida came to Bangladesh with her husband from Nasha Phuru village in Myanmar Reuters Rohingya mothers face persecution Rehana Begum lays her one-day-old daughter in front of her inside their tarpaulin shelter. Rehana fled her village of Jambuinna in Myanmar three months ago. 'We were in our home and suddenly the military came to our village and started shooting. When we heard the sound of gun shots we immediately went to our relatives. We walked for four hours without any food and water to reach the border at 1 a.m. We paid 25,000 Myanmar kyat (£14) to a broker to cross.' Intercepted by Bangladesh border guards, Rehana's family narrowly escaped being sent home. 'They wanted to send us back, but then we heard gunshots from the Myanmar side and the guards released us, saying, "Stay in Bangladesh and save your lives"' Reuters Rohingya mothers face persecution Noor Begum sits next to her one-day-old daughter Sumaiya as she stares into the camera. Noor came to the camp one-and-a-half months ago from Nagpura village with her husband Jahangir Reuters Rohingya mothers face persecution Rajuma Begum observes her one-month-old son Raihan. 'I fled to Bangladesh because of fear, because I needed to save my children. I was pregnant and suffering from fever while crossing the border. I also have an 11-month-old boy, so it was very difficult to reach the border from our village Wabek in Myanmar. I had to rest frequently. After six hours of horrible walking we finally reached the border at 2am and crossed after paying a broker' Reuters Rohingya mothers face persecution Eighteen-year-old Asmot Ara rests her newly born daughter on her lap. Asmot said she came to the camp one month ago with neighbours from Nagpura village. In Myanmar her father-in-law was killed and their home burnt down by the Myanmar military Reuters Rohingya mothers face persecution As Marijaan holds her 25-day-old daughter Noor Habi, her son peers over her shoulder. Marijaan fled to Bangladesh from Khyeri Prang village in Myanmar one month ago after her house was burnt down by the Myanmar military. 'I reached the border at night and crossed by the boat. I paid the boatman to cross the Naf River' Reuters

A senior government official in Bangladesh, which has complained of being burdened by the heavy flow of refugees, has said India was helping it solve the crisis.

More than 75,000 Rohingya have fled to Bangladesh since 9 October after an insurgent group attacked Burma border police posts, prompting a security crackdown in which troops have been accused of the murder and rape of Rohingya civilians.