For a start, no-one - not even a bailiff - has a right to enter by force, although they can obtain a warrant to enter from a court. If they're on unsteady ground to start with, though, it's unlikely they'll do that.
If your brother has thugs (and by that, I take it, you mean bailiffs?), on the doorstep threatening to enter by force, then he should call the police on 999.
If they're actual TV licencing people, then they should have records to the effect that there is not, and has never been, a TV on the premises whilst your brother has been there. All he would need to show is some evidence of when he took over ownership/tenancy. They have the technology to be able to know whether or not there has been a TV there during that time.
I think all TV licencing people can do is to confiscate the telly if he doesn't have a licence, so he may as well invite them in to see if they can find one to take.
Bailiffs should only be calling if the matter has been through a court and a fine has not been paid. If they're allowed onto the premises, they can seize any goods to the value of the fine.
In some ways it would be good if the licencing people did take it to court, because then he could just put his case forward with his supporting evidence and make fools of them.
If he wants to make it public, he needs to contact his local TV stations and also his local paper. I know from experience that things get done very quickly once the media get involved.