The website of British independent broadcaster ITV reports that the investigation comes after the watchdog received 1,150 complaints. Jules O'Dwyer is a British expat, who lives in Belgium. She told ITV she was "shocked and surprised" by the backlash to her win.
Jules O'Dwyer won a place on the Royal Variety Show as well as the 350,000 euro prize when she beat a Welsh choir to come first in Britain's Got Talent.
An Ofcom official told ITV: We've opened an investigation to determine whether viewers of ITV's Britain's Got Talent final, who may have paid money to vote, were misled about the competition."