Mangaldoi wildlife division conservator of forests Sushil Kumar Daila said Md Giyasuddin Ahmed was produced at the chief judicial magistrate court in Tezpur which remanded him to five days' police custody on Saturday.

"Circumstantial evidence points the needle of suspicion towards Giyasuddin for the murder of home guard Sushil Sil on the night the rhino was killed. After interrogating other staffers and consulting firearms experts, we started suspecting Giyasuddin. Another accomplice, Nizamuddin, who was involved in the crime, is absconding," said Daila.

"We deployed sniffer dogs which took us straight to Nizamuddin's house, located close to the poaching site. Nizamuddin had fled his house by the time our staff reached there. We do not want to reveal the other names involved in the racket for the sake of investigation," he added.

Daila said the suspicion on Ahmed grew stronger after he started giving different statements on the killing of Sil and rhino poaching. He added that both Sil and Giyasuddin were at the Belsiri anti-poaching camp near where the rhino was poached.

"The bullet injury mark on Sil's body, the blood stains on his cap and the distance from the place where the rhino was poached did not match with Giyasuddin's argument that Sil was killed during an encounter with the poachers. Rather, the bullet which killed Sil was fired from a close range. Sil's rifle was found beneath his body, which is very unlikely, if he was killed in an encounter. The accused stage-managed everything to show that Sil was killed in an encounter," said Daila.

He added that the wireless messages relayed by Ahmed to other camps at the time of poaching indicated that he intentionally suggested a longer route to the forest guards to reach the spot.

Orang has 100-odd rhinos. Poachers managed to kill two rhinos in 2014, even as park authorities successfully foiled several poaching attempts in the park.