Liverpool FC has "requested a formal investigation" after violence was used against its fans before the Champions League final against Real Madrid in Paris.
Security at the Stade de France appeared to have been overwhelmed by the size of the crowd, leaving many supporters waiting outside the ground for hours.
Sky Sports News' chief reporter, Kaveh Solhekol, was among those tear-gassed at the stadium.
Shortly afterwards, he described what he had witnessed: "In the last few minutes, me and three of my crew were tear-gassed for no reason whatsoever by the French police. It was a pretty nasty experience but we sorted it out by getting a few bottles of water and pouring it in our eyes. We are all fine.
"The situation here is a bit of a strange one. I think what has happened is a lot of people have turned up at the stadium without tickets. They seem to be young, French people just milling around and trying to break through the security cordons.
"From what I've seen, even at the Liverpool fan park, the French police's attitude has been very heavy-handed with absolutely zero tolerance. They don't care how much of a crush is developing and they are insisting on searching absolutely everybody before they let them through.
"We had a situation at the fan park this afternoon where some Liverpool fans were queuing up for three hours to get into a free event. There were three, four, five checkpoints where they were being held up and searched.
"We had the same situation at the stadium tonight. There are so many police, riot police and security guards here and their mindset has been to stop anybody without a ticket getting anywhere near the stadium.
"The situation is complicated because we're not just talking about paper tickets - in the modern age, people have passes on their phones. They haven't been able to bring up the right passes or find their passwords. We've seen people in tears because they've had their tickets swiped from them. People have had their electronic tickets stolen from them.
"As far as the police and security here [at the Stade de France] are concerned, they don't care. They don't want anybody near the stadium if they don't have tickets. I'm walking around the streets now and it's full of young, French people trying to find a way to get inside the security cordon.
"I can only say what I've seen as an eyewitness myself, but I haven't seen any Liverpool supporters whatsoever causing any problem at all. I haven't seen them turning up late - I was quite shocked at how early supporters had turned up at the stadium.
"We got here about four hours before kick-off, expecting it to be quite quiet. But it felt like it was an hour before kick-off because so many people had arrived early and in good time. I would be very wary when I read statements from UEFA blaming the kick-off being delayed and the problems outside the stadium on the late arrival of fans. That is not the case from what I have seen.
"I have seen quite a few fans trying to trick their way past security guards and the policemen and all of those supporters I've seen trying to do that are Spanish. It was one of those incidents we got caught up in when we were tear-gassed - a group of riot police were trying to eject some Real Madrid supporters who were trying to get through the cordon without tickets.
"There was a bit of a confrontation between the Spanish supporters and the riot police, and that's when they got out the tear gas and we happened to be in the wrong place at the wrong time.
"But I have to stress again - with my own eyes, I haven't seen any Liverpool supporters causing any problems or trouble whatsoever."