Celtic striker Leigh Griffiths has been issued with a more serious charge by the Scottish Football Association after being accused of "singing in public a song of an offensive, racist and/or discriminatory nature".

Griffiths was last week hit with a charge of not acting in the best interests of football by "singing about Hearts in administration" and the notice of complaint was updated after SFA compliance officers watched fresh footage, which emerged at the weekend.

This appeared to show the Scotland international singing in a pub with Hibernian fans as they chanted a derogatory song about former Hearts player Rudi Skacel.

Griffiths, whose actions are also under investigation by police and his club, has now been accused of bringing the game into disrepute.