MILWAUKEE -- An anonymous source is offering $100,000 for the safe return of a nearly 300-year-old Stradivarius violin stolen from the Milwaukee Symphony Orchestra's concertmaster.

The rare violin was on loan to Frank Almond from an anonymous donor.

Milwaukee Police Chief Edward Flynn has said the robber used a stun gun on Almond and took the instrument Monday evening in a parking lot at Wisconsin Lutheran College, where Almond had just preformed.

The reward is offered to anyone who can provide information which results in the violin's safe return.

The Milwaukee Symphony Orchestra's President and Executive Director Mark Niehaus says the organization is hopeful the reward will help in the violin's recovery.

Milwaukee police are investigating and haven't made any arrests.