Video footage of supporters apparently singing a sectarian song in the El Sadar stadium after last week's UEFA Cup match against Osasuna has been posted on the internet.

UEFA have confirmed they are "fully aware" of the footage less than a year after fining Rangers £13,000 for discriminatory chanting in a Champions League tie against Villarreal.

And fans chief Macmillan now fears the club will face serious sanctions - such as being forced to play behind closed doors - despite the efforts of Rangers chiefs and fans groups to stamp out bigotry in recent months.

"It's very disappointing," he said. "The club and the majority of the supporters have done their damnedest to eradicate this kind of thing.

"Now these morons have come out with this nonsense and I really don`t know what can be done to sort this out now.

"It doesn't matter how often they are told, some people will just not listen to the club.

"I just hope the pictures are clear enough that Rangers can identify some of these people because they should be locked up and left to lie in jail.

"It`s an absolute disgrace and heaven knows what UEFA will do about it - I`m frightened to even think about it."

Macmillan added: "Things were going nicely until this latest situation and no-one can defend it. No right-minded person could condone it.

"We all know the consequences after the Villarreal game and we know the sanctions that could be imposed by UEFA.

"The club has made several appeals and no real fan would behave like this knowing the sanctions we could face, such as playing behind closed doors.

"I think the people who were involved would do the same whether they were at a football match or not - they are not real football fans."

Rangers are already waiting to hear whether UEFA will launch an investigation into claims of heavy-handed policing at the match.

Rangers supporters claimed riot police charged into their section for no reason, lashing out with sticks, fists and kicks before, during and after the match in Pamplona.

The Glasgow club have since officially complained to UEFA about the lack of segregation and policing at the match but Macmillan fears any probe will now be overshadowed by fresh allegations of sectarianism.

He said: "It`s an important issue because the Rangers supporters got a raw deal.

"Apparently the local police in Pamplona were very good before the game but the ones who were brought in for the game just went wild for no apparent reason.

"I don`t know if UEFA will take sanctions against Osasuna or not - I just hope what happened doesn`t get lost because of this latest nonsense."