Indian police have arrested a senior army officer for the murder of a journalist shot dead while investigating allegations of financial fraud against him.

Reporter Sudip Dutta Bhaumik was allegedly killed by a junior officer when he went to a paramilitary base in the northeastern state of Tripura on Tuesday to investigate a story.

Police said Tapan Debbarma, the commandant of the second Tripura state rifles, was arrested Wednesday on charges he ordered his bodyguard to shoot the reporter.

He has been remanded to 10 days of police custody.