India has extended its ban on Islamic scholar Dr Zakir Naik's Islamic Research Foundation (IRF) for another five years, accusing the organisation of promoting religious hostility and activities threatening national security.

The Ministry of Home Affairs announced the decision on Friday under the Unlawful Activities (Prevention) Act, a day before the previous ban was due to expire.

In an official statement, India's Home Minister's Office accused the organisation of having "sinister anti-India designs", including inciting communal hatred and promoting terrorism.

The statement also alleged that the foundation had encouraged separatism, violent unrest and religious discord.

Naik, a Mumbai-born Islamic scholar known internationally for his religious lectures and comparative discussions of Islam and other faiths, has repeatedly denied supporting terrorism or encouraging violence.

Responding to the original ban in November 2016, he described the decision as politically and religiously motivated.

In an open letter published at the time, Naik said the government had decided to ban his organisation before completing its investigations.

He also rejected accusations that his speeches had encouraged violence, maintaining that he had consistently advocated peace and condemned terrorism.

The IRF challenged the ban before an Indian tribunal, arguing that it was a registered charitable organisation that had never engaged in unlawful activities.

Its lawyers maintained that the government's allegations did not establish grounds for banning the foundation.

No fresh response from Naik or the IRF to Friday's extension was immediately available.

Naik has been living in Malaysia since 2016, after leaving India amid investigations into his activities. He holds Malaysian permanent-resident status, which authorities publicly confirmed in 2017.

India has sought his extradition over allegations including money laundering and incitement to religious hatred.

Naik has denied wrongdoing.

The Indian government first banned the IRF in November 2016 and renewed the restrictions in 2021.

In its latest notification, India's Home Ministry alleged that Naik's speeches were "objectionable and subversive" and could encourage religious hostility.

The ministry said the organisation's continued activities could threaten communal harmony and national security if restrictions were lifted.

The renewed ban will remain in force for five years, subject to the provisions of India's anti-terrorism legislation.