The alleged incident could land the Celtic striker in more trouble with the ruling body and his club.
The 23-year-old former Hibernian player has already been fined by the Parkhead club and faces SFA disciplinary charges after he was filmed singing about administration-hit Hearts’ financial problems in a bar before the Edinburgh derby at Tynecastle last Sunday.
Celtic manager Neil Lennon warned Griffiths, who joined the Scottish Premiership champions from Wolves in January, that the transgression was “his one strike”.
The Celtic boss added: “I don’t want him doing any more - otherwise his career at Celtic won’t be as long as he maybe wants it to be.”
Griffiths was charged with a breach of disciplinary rule 86, which covers “not acting in the best interests of Association Football”.
Fresh footage from the same bar shows Griffiths standing up and dancing about among Hibs fans as they sing the song about Skacel.
Lunny could issue a second charge to the Scotland striker but more likely, the charge will be re-issued taking into account the new footage which would make it a more serious matter.
In 2005, former Hibernian forward Derek Riordan was fined by the Easter Road club and forced to apologise to Skacel when he was filmed singing the same song in a pub with other fans but that incident pre-dated judicial panel protocol.
Celtic were unavailable for comment.
Meanwhile, Anthony Stokes has fired out a warning to Premiership defences by targeting an average of a goal a game in the final five fixtures.
The Celtic striker scored his fourth in four games in the 2-0 win over Dundee United at Tannadice on Saturday to take him to 15 for the season.
After Georgios Samaras had put the visitors ahead in the fifth minute from a Kris Commons free-kick, the Republic of Ireland striker worked a one-two with the former Derby and Nottingham Forest attacking midfielder before firing high past Radoslaw Cierzniak.
It was the highlight of a Celtic performance described by Lennon as “magnificent” and Stokes insists neither he nor his team-mates will slack off in the post-split games.
He said: “There’s plenty of games to go this season and just because you win the title it doesn’t change your mentality.
“You want to go out and win every game.
“I would like to get to 20 goals or above if I can. I have scored three in the last three games so I am happy with my form and (another five in the last five games) can be easily done.
“I have done it before, gone on runs of seven or eight games but as long as we are winning games, it doesn’t matter.”
United boss Jackie McNamara admitted his side were “poor, too deep, tentative in our passing and too nervous” in the first half against his former side and is looking for them to come out of the traps quicker in next week’s William Hill Scottish Cup semi-final against Rangers at Ibrox.
He said: “There are a lot of people have Rangers as favourites. I don’t look really look at it that way.
“It is for experts to decide who is favourites and who is not. It doesn’t matter once you cross the line. It is who performs on the day and takes their chances.”