"NSCN (I-M) operatives from the Muslim community have been maintaining direct or indirect links with extremist groups such as Harkat-ul-Jehadi-Islami and other criminal elements suspected to be having links with terrorist organisations," Rio said.
It is emerging that the NSCN (I-M) has some active Muslim members in their ranks who play a major role in the group's extortion drive in Dimapur, he told the Chief Ministers' conference on internal security in New Delhi.
"Such operatives are in contact with 'one' Lieutenant' Halal Uddin from NSCN (I-M) armed wing and one Azad alias Robin from the civil wing," Rio said adding that they are reported to have very close links with one so-called commander of the group in its transit camp in Bangladesh.
"In such backdrop, there is strong possibility of Islamic extremists establishing 'sleeper cells' in Nagaland by taking advantage of their contacts inside the state," he said.
Another possible scenario is that these extremist elements may develop differences with NSCN (I-M) and form a new organisation, he said.