The National Investigation Agency will take over the inquiry into a chemist’s murder in Maharashtra’s Amravati city to check the “involvement of organisations and international linkages”, the home ministry said on Saturday.

The police suspect that the 54-year-old chemist, Umesh Kolhe, was killed on June 21 for sharing a post supporting suspended Bharatiya Janata Party spokesperson Nupur Sharma, PTI reported. She had made disparaging remarks about Prophet Muhammad during a debate on Times Now television in May.

On June 28, a week after Kolhe’s murder, tailor Kanhaiya Lal was killed in Udaipur for supporting Sharma. The National Investigation Agency is also inquiring into Lal’s case.

Five men have been arrested for allegedly murdering Umesh Kolhe, PTI reported. Amravati Police Commissioner Aarti Singh on Saturday said that the officers are still searching for the prime accused Irfan Khan.

Umesh Kolhe was murdered between 10 pm to 10.30 pm on June 21 when he was on his way home after shutting his shop. His son, Sanket Kolhe and his wife Vaishnavi were accompanying him on a scooter.

Sanket Kolhe told the police that two men stopped his father’s bike, and stabbed his neck with a knife, The Indian Express reported. “My father fell and was bleeding,” he said in his complaint. “I stopped my scooter and started shouting for help. Another man came and the three fled the spot on the motorcycle.”

Umesh Kolhe was taken to the hospital where he succumbed to his wound.

Sanket Kolhe told The Indian Express that his father was not associated with any political party. “I also heard that he was murdered over his social media post, but I checked his Facebook profile and did not find anything objectionable,” Sanket Kolhe said. “Only the police can tell what the motive was. I am blank. But I can say for sure that he was not murdered for robbery.”

An unidentified officer said that during the investigation, the police found that Kolhe had circulated a social media post supporting Sharma on WhatsApp. He allegedly posted the message on a group with Muslim customers.

One of the arrested accused said this was an insult to the Prophet and hence Umesh Kolhe must die, the officer added.

Tushar Bharatiya, a BJP leader in Amravati, alleged that Umesh Kolhe was indeed murdered for supporting Sharma, NDTV reported.

“People in the police department also think so,” he claimed. “We have learnt that the killers have admitted to murdering him because of supporting Nupur Sharma, but the police are trying to cover it up.”