The families of the victims had named members of the Bajrang Dal in their complaint to the police.
One of the five men accused in the death of two Muslim men from Rajasthan whose charred bodies were found in an SUV in Haryana after they were allegedly kidnapped by cow vigilantes has been arrested, the police said on Friday.
In a statement, the Rajasthan Police said Rinku Saini, 32, a resident of Firozpur Jhirka in Haryana's Nuh district, was arrested based on questioning and other evidence. Saini, a taxi diver, was involved with a cow vigilante group, the police said.
The families of the victims had named Saini and four others as members of the Bajrang Dal in their complaint to the police.
Nasir, 25, and Junaid alias Juna, 35, both residents of Ghatmeeka village in Bharatpur district of Rajasthan, were allegedly kidnapped on Wednesday and their bodies were found inside a burnt Bolero SUV in Loharu in Bhiwani in Haryana Thursday morning.
Senior Rajasthan Police officer Shyam Singh said a First Information Report or FIR was registered at Gopalgarh police station against five people - Anil, Srikant, Rinku Saini, Lokesh Singhla and Mohit Yadav alias Monu Manesar.
Rajasthan Chief Minister Ashok Gehlot condemned the killing and promised stern action against the accused.
"One accused has been taken into custody and the search for the remaining accused continues," he tweeted in Hindi.
Alleging that its youth wing Bajrang Dal's name was being dragged into the case due to "political bias", the Vishva Hindu Parishad (VHP) demanded a CBI probe into the incident.
"It seems that without a preliminary investigation, the Rajasthan Police have assumed that the names taken by the smuggler's brother are responsible for the incident," VHP joint general secretary Surendra Jain said at a news conference in Gurugram.