Treasury Minister Eddie Teare says threatening letters sent to his home address have had a 'profound effect' on his family.
He is offering a cash reward in return for information.
Meanwhile, the police have released excerpts from the letters in the hope that somebody will recognise the handwriting and identify the author. Police say they are not releasing the exact nature of the threats to protect the integrity of any future prosecution.
Mr Teare said: 'Conduct of this nature is totally unacceptable. It has had a profound effect on my family. I am offering a personal reward in return for any information that will help the police with their enquiries. I would appeal to anyone who knows who is responsible to come forward. I have decided to put up the cash reward to assist the investigation and hopefully prevent others in the community having to experience what my family is going through.'
Anyone who recognises the handwriting is asked to contact Ramsey police station on 812234.
Inspector Andy Kneen said: 'the threatening nature and language used within the body of these letters falls well outside what is acceptable and would appear to form the basis of a criminal offence. A number of avenues of enquiry have so far been pursued, and some remain open.'
Got a story? Contact Joanne on 340000 or email newsdesk@manx.net
twitter @jonewsiom