Bucharest, Apr 9 (IANS): Romanian assistant referee Octavian Sovre has explained his asking Borussia Dortmund's Norwegian striker Erling Haaland to autograph his red and yellow cards by saying he regularly does so at matches and donates them to charity.

The official told the playsport.ro portal on Thursday that Haaland's signed items would be used to raise funds for an organisation which supports those suffering from autism, DPA reported.

Sovre raised eyebrows when he was filmed by broadcaster BT Sport asking Haaland to sign the cards on way to the dressing room after Tuesday's Champions League quarter-final first leg in which Manchester City beat Dortmund 2-1.

UEFA, the European football's governing body, said it would not comment on the matter.

The SOS Autism organization in Romania thanked Sovre for his contribution and chairman Simona Zlibut told the gsp.ro portal donations were needed for it to survive.

Sovre believes he has had gathered around nine autographs for the charity including nine from Barcelona superstar Lionel Messi - albeit usually more discreetly than in front of a camera.