Social media has been abuzz after footage showed an Irish flag being removed from a billboard at Dens Park during their league clash on St Patrick's Day. 

Video circulating around Twitter showed the Irish flag being removed during Celtic's 1-0 win over Dundee on Sunday.

And the fan who had his flag removed said afterwards he was told to leave the ground after he went to retrieve it from stewards. 

While supporters groups voiced their disgust at the actions, Dundee said the reason was not sinister - stating simply that the flag breached rules as it was covering advertising.

Police Scotland said were were a total of two arrests and 16 ejections from the ground, with seven refusals of entry, during the match but said that incident over the flag was a matter for the stewards.

READ MORE: Celtic fans arrested after 'aggressive' incident in Dundee

Fans Against Criminalisation, the group set up to move for the scrapping of the Offensive Behaviour at Football and Threatening Communications (Scotland) Act 2012 criticised the overpolicing of Sunday's match A FAC representative tweeted: "I am explicitly saying that it is entirely legitimate for someone who in any way, shape or form identifies with Ireland to take such a flag to a Celtic game. This does not necessarily have a political connotation. But even if it did, that wouldn’t be an issue either.

"If a Rangers fan identities with the Union Jack then they have every right to wave one too. Wouldn’t take any issue with that either seeing as we live in an apparently free and democratic society.

"If members of Scotland’s multi-generational Irish community, who make up much of the Celtic support, wish to celebrate the country of their ancestors why do you have a problem with that?"

READ MORE: Police arrest pitch invader who confronts Rangers captain James Tavernier

The flag was being displayed in the away end during Sunday's Scottish Premiership clash until it was take away. Footage shows a Celtic fan pursuing those who removed it and confronting them, before finally getting his flag back.

And Joe O'Rourke of the Celtic Supporters Association who was concerned over what he perceived was a larger than normal police presence added: "There seemed to be a few incidents yesterday, one looked like a total farce when an Irish National Flag was pulled down by stewards who then ran away with it.

"There is absolutely nothing offensive about the National Flag of Ireland, so it’s hard to understand the actions of the steward. As far as I know, the owner got the flag back, so it begs the question, why take it in the first place?

He added in a blog post: "I have been following Celtic for over sixty years, I’m 68 years old and can walk down any street in Scotland without getting a second look from any copper, but once I put on my Celtic scarf and jacket I somehow become a threat to society."

But John Nelms, managing director at Dundee, said: "The flag itself was taken down because it was covering up a board that was paid for by patrons that support the club.

"That's the only reason it was taken down."

Some fans, however claimed that at least two banners were displayed covering advertising in the Dundee end, seemingly without being asked to remove them.