Indian Home Minister Rajnath Singh on Thursday reiterated that Rohingya Muslims living in India are not refugees but illegal immigrants from Myanmar.
The Indian home boss said objections to deport them are baseless since Myanmar has expressed its willingness to take them back.
They are not refugees, nor have they taken asylum, the minister said of the nearly 40,000 people who the Centre has said it will remove from India, provoking international criticism.
On Monday, the Indian government told the Supreme Court that it will confidentially share intelligence information with judges showing Rohingya links with Pakistan-based militants.
The Supreme Court is deciding an appeal lodged on behalf of Rohingya against the deportation plan. The Home Ministry submitted written details arguing that the hardline stance is justified by the security threat posed by illegal immigrant Rohingya, hundreds of thousands of whom have fled from Myanmar to Bangladesh, from where many have crossed into India.
The Rohingya are denied citizenship in Buddhist-majority Myanmar and regarded as illegal immigrants, despite claiming roots that date back centuries.
The Home Ministry said the illegal influx of large numbers of Rohingya into India began four to five years ago, long before an exodus that saw more than 4,00,000 Rohingya flee to Bangladesh since August to escape a Myanmar military counter-insurgency offensive that the United Nations has called "ethnic cleansing".
The court will next hear the matter on October 3.
The government told judges it has received information on Rohingya involvement in plots by ISIS and other "extremist groups" to ignite communal and sectarian violence in India.
Senior Home Ministry official Mukesh Mittal said the government will privately show the court material gathered from "sensitive investigations" to substantiate the claims in its affidavit.