The winner of "Eurovision" convicted of violation of the main rule of competition

The singer Duncan Lourens, representing Netherlands on "Eurovision", violated the main rule of competition; offense of the performer can lead to revision of results competitions. It appeared that Duncan Lourens made on "Eurovision" the song which already was in its repertoire. Video of its performance was published on YouTube (after the first minute) in 2017. On "Eurovision" on Saturday he made the same song and won first place, having gained 492 points. Thus, according to "Eurovision" requirements, the song has to be written specially for competitions...