Bhubaneswar, Aug 21 - Maoist rebels have threatened to blow up the residence of Orissa Finance Minister Prafulla Ghadei and kill his son, police said Friday.

The letter was received at the office of Orissa Mining Corporation at Jajpur Thursday. The Maoists have also threatened to blow up the office of the mining corporation and a ferrochrome factory.

'The officials of Orissa Mining Corporation told us about the letter. We have filed a case and are investigating the matter,' a police official said.

The letter also warns that Ghadei's son Pritiman, a legislator from Korei, would be eliminated, the official said.