I found an interesting message from the Finnish Air Force HQ's diary which contains information of a plan to shoot down a Soviet courier plane flying from Stockholm to Russia on 30 June or 1 July 1942. The Finns had a spy of some sort feeding information to them when the Douglas DC-3 (or PS-84) was suppose to take-off from Stockholm towards east. They even went the trouble of redirecting all Aero Oy flights from Helsinki to Stockholm to avoid any identification mistakes.
At the end of the message it is mentioned that all of the information should be also forwarded to Luftflotte 1, so that their planes also could be ready to "shoot down all Douglases they will see".
However I did not managed to find anything else regarding the plane. During those days there was two seperate search flights flown by Fiat G.50s from Lentolaivue 26 from Helsinki towards south. It seems that the Finns abandoned the plan do of lack of information or did not managed to catch the plane on time.
Is there any information regarding the flight in German or Soviet sources?
http://digi.narc.fi/digi/view.ka?kuid=4447887 (the message in Finnish)