Pellet Crossbow??
 

I found this unusual crossbow in second hand shop. I had bow string made for it. I found it shoots in an arc with a bolt, after further research I believe it to be a pellet crossbow. Please help me ID where this could have been made and what type of crossbow is it.

With the buttstock shaped as it is, it looks like a modern version of the old stone -bow.
For one of these (if it is!) you need two strings with spacers holding them apart, and a small 'basket' or pouch for the stone.

The pics are a bit fuzzy, but it looks like the posts are a little close together at the front.

Stone -bows were accurate & deadly little devices, for taking birds and small game, & used even in the 18th & 19th century. They were also popular with ladies.

Best,
Richard.

Stone Bow!
 

OK that makes more sense, so I am right it needs a double bow string with a pouch and spacers.

Correct, a doubled string and pouch will be necessary. You might want to locate Helmut Nickel's article, "Stone-bows in the Old and New Worlds" in ARMS AND ARMOR ANNUAL (ed. Rob't Held, Chicago: Follett 1973), which shows examples from several cultures and from these you can get a good idea as to the various ways that a functional version can be made for your crossbow.