According to Sky Sports, Stamatelopoulos has reached an agreement on a three-year contract with the Scottish Premiership side.
The Australian international has made a notable impact in the A-League, netting 24 goals in 60 appearances.
Stuart Kettlewell said: “We’re well down the road in trying to make something happen.
“I would love to try and get another couple of players at the top end of the pitch, but sometimes my want and the actual realism of it can be difficult, but I can assure you that we’re really far down the road when it comes to that striker position.
“I would like to try and bring a slightly different dimension to the front end of the pitch as well, which we’re working away on.”