Local journalists told CPJ police arrested forest warden Zamman Jinnah in connection with the death. He was released on bail. Two other suspects, who are not forestry service employees, are still being held by police, the local journalists added.
Jinnah had made death threats against Goala soon after his articles on corruption in the forestry service appeared, The Assam Tribune reported.
"We condemn the killing of our colleague Prahlad Goala," said CPJ Executive Director Ann Cooper. "We call on the authorities in Assam to conduct a thorough investigation and bring those responsible to justice."
Goala, 32, was riding a motorcycle near his home in eastern Assam's Golaghat district when he was apparently rammed by a truck. When police arrived at the scene, they found that Goala had been stabbed several times.
Local journalists' organizations and civic groups staged a protest in Golaghat on January 10 and called for a full investigation into his death.
CPJ is continuing to investigate the circumstances of Goala's death to determine whether he was killed in retaliation for his work.