ONE of Scotland's leading legal figures has condemned a police response to a protest by a group of Celtic fans, claiming the incident smacked of a "police state".

Brian McConnachie, QC, said the incident, in which 13 supporters were arrested as officers moved to halt an unauthorised march to Celtic Park, could have been resolved earlier in the week by police.

He also cast doubt on the police official version of events, claiming the numbers who arrived on the scene armed and with cameras indicated they were not, as indicated, responding to reports of a large gathering.

Legal representatives of those arrested, most of whom are believed to be members of the Green Brigade, said they expected numerous complaints to be made to the police over the controversial "kettling" tactics and are collating video evidence.

The incident, which saw more than 200 officers, many on horses and with batons drawn, has also drawn criticisms from a number of politicians.

One source said senior police figures have expressed disquiet about how the incident was handled and fear it was a public relations disaster for the force.

Videos of Saturday's incident on Glasgow's Gallowgate have been posted on social media sites and come on the back of allegations by lawyers on the treatment of fans from all clubs under Offensive Behaviour at Football legislation.

The Green Brigade, which has been praised and criticised in equal measures by other fans, authorities and Celtic FC, announced mid-week it intended to march to the game against Aberdeen over allegations of mistreatment since the laws were introduced a year ago. But, before setting off, police moved in to halt them on the roads.

Mr McConnachie said: "From what I've seen, this is total overkill. I don't care which team you support. How can this be considered a proportionate response to what seemed to be a peaceful protest. We'll know pretty soon exactly what went on, given the amount of video footage.

"It's a fine line between an unlicensed procession and a police state. If the police believed there was going to be an issue they had days to resolve it. They'd an opportunity to discuss it. It's pretty clear 200 officers with cameras and batons just seemed to be on hand for an unexpected incident."

He added: "I've some degree of sympathy with the police. The SNP Government, the Crown Office and our 'Green Brigade supporting' Lord Advocate Mr Mulholland have created a policy, made it such a big issue police have no option but to react in a particular way. We're also seeing this treated at summary level by sheriffs who are not inclined to disbelieve police."

Paul Mullen, from solicitors Livingstone Brown, said: "Some clients have asked about the formal procedure for making police complaints and a couple will be seeking recompense for injuries received by themselves and in one case their children as a direct result of the action of police officers.

"In all the circumstances, I very much doubt Strathclyde Police will have heard the last about the events of Saturday."

A spokesman for Gildeas solicitors, also dealing with football fans facing prosecution, said: "This incident is not just a matter for Celtic fans. It should raise genuine concerns for Rangers fans as well. One wonders how the police will attempt to justify their actions. The footage seen so far makes for some interesting questions."

On Twitter, Lothians Labour MSP Neil Findlay said: "As predicted in parliament Offensive Behaviour at Football Bill being used to criminalise working class young men – Old Firm fans singled out."

SNP group leader on Glasgow City Council Graeme Hendry denied the incident was political, but said he was seeking a meeting with the police following complaints by constituents.

In a letter to the head of Strathclyde Police Authority, Mr Hendry said: "I have been contacted by constituents concerned at the behaviour of Strathclyde Police on Saturday. Having seen photos of the kettling technique seemingly employed by the police on Saturday, I would also add my own concern at the appropriateness and proportionality of this technique.

"Given these concerns, I would ask that you launch an investigation into what happened on Saturday and see what lessons can be learned for policing in the future. Additionally, I would hope that should it be accepted the techniques used were not appropriate or proportionate an apology and action will be forthcoming?"

A Strathclyde Police spokeswoman said: "Any complaints will be fully investigated and we will examine all footage."