Mangaluru East (Kadri) police arrested Puneet Raj Kottari, the city co-convener of Bajrang Dal, following a complaint against him and 21 others by Vidya Dinker, said police commissioner S Murugan.
Activists of the right-wing outfit had stopped the screening of the film at theatres here from December 20 in protest against Khan's comments on intolerance in the country.
Dinker, in her complaint, said that the Facebook page 'Veera Kesari' and its followers had uploaded remarks threatening to physically assault, rape and kill her.
Dinker, the co-ordinator of Citizens Forum for Mangalore Development, had lodged a complaint against unidentified Bajrang Dal activists for disrupting the screening of 'Dilwale'.
Meanwhile, Pandeshwar police arrested six persons in connection with the case of the forcible stopping of the screening of 'Dilwale'. They were later released on bail, police said.