The match in question was played in the Swedish capital on Tuesday. The ACSU "noticed unusual betting patterns on the game" and is likely to get in touch with leading betting firms, including Betfair, in an attempt to get a clearer picture, claimed a report in 'ESPNcricinfo'.
The development comes right after Hong Kong's 5-wicket victory in the first qualifying playoff, which booked them a berth at the 2016 World Twenty20 in India.
The tournament will be held from March 11 to April 3 next year. Chasing 161 runs for a win, Hong Kong won the match by five wickets thanks to Babar Hayat, who scored 20 off nine balls.
Mohammed Nabi of Afghanistan conceded 16 runs in the last over. Despite the defeat, Afghanistan still have a chance to qualify for the mega-event.
They play Papua New Guinea today in the third qualifying play-off.