The man had taken classes for 11 of the 21 persons from Kerala who are missing and are suspected to have joined the IS, they said.
"We have taken a person into custody. Verification is on. As of now, we cannot conclude if he has any links with IS," Kannur District Police Chief Kori Sanjaykumar Gurudin told PTI.
Mohammed Hanif, who hails from Kambalakkad in Wynad was taken into custody from Panur last night, police said.
Hanif is reported to have worked as preacher in various places, police said.
On August 8, police had said of the 21 persons who went gone missing from the state, 17 were from Kasaragod and four from Palakkad.
They include four women and three children. Their disappearance came to light last month after the families approached officials in Kasaragod.