A freelance journalist from the United States who was covering the Sterlite copper plant case in Tamil Nadu’s Thoothukudi district was asked to leave India for allegedly violating visa rules, reports said on Tuesday. Superintendent of Police Murali Rambha said he, as foreigner registration officer in Thoothukudi district, issued Mark Scialla a Leave India Notice, The Hindu reported.

Scialla left for Madurai by road around 7 pm on Monday, the police said. He was supposed to take a flight via Hyderabad and Doha to the United States.

At least 13 people were killed in police action on protestors during demonstrators against Vedanta’s Sterlite copper plant in Thoothukudi last May. The state government subsequently shut down the plant, but in December, the National Green Tribunal overturned this order.

The police had placed the hotel Scialla was staying at in VE Road under surveillance for two days. They interrogated him for many hours after he was found visiting villages around the Sterlite plant, which are under heavy security following the protests. After questioning, the police asked Scialla to leave the country within 48 hours.

Scialla arrived in India on December 3 on a tourist visa which was valid till January 21, The Times of India reported. He intended to leave Thoothukudi on January 3 and India on January 12. “During inquiry he admitted that he came on a tourist visa and wanted to do an article and a film on the anti-Sterlite protests, which is a violation of visa norms,” Rambha said.

But Rambha said that no case had been registered against the journalist as he did not engage in any other activity. People associated with him – including anti-Sterlite protesters Fathima Babu and Raja, Regan and Prince Cardoza – have been called for questioning on Wednesday.