police impounded my car

6 days ago police came to my home,asked for proof of ownership of my car,I showed them the title(legally plated in my name)& they took the car & title!No one will discuss with me why they took my car other than to say its stolen & is being investigated.I purchased the car in April from a business (I have the purchase receipt)I registered/plated it my name through the DMV. Meanwhile, the tow bill is adding up 30.00 each day (already approx 200.00)My questions:Can they do this?How long can they hold my car?When proven it is not stolen, do I have to pay the impound fee to get my own car back?Any advise/information I can get as soon as possible would be greatly appreciated.