During the first few minutes of the UKUncut protest at Sir Philip Green's flagship Topshop store on Oxford Street on Saturday, burly men in nondescript clothing were seen shoving protesters out of the shop. These men appear to have been plainclothes security guards, but they were showing no identification to distinguish them from members of the public.

The two men pictured (excuse the blur) are on film shown by Channel 4 News manhandling protesters. They were also present throughout the whole protest, observing from the side of the street. When asked who they worked for, the men refused to identify themselves, and said they did not “work for any company”. But if they weren't working for Topshop, who were they working for? And what were they doing throwing people out of the store?

Security personnel should be licensed by regulatory body the Security Industry Association (SIA). The conditions of these licenses state that security staff must “wear the licence where it can be seen at all times when engaging in designated licensable activity”. Licensed security staff can hide their licenses if “the nature of their conduct on that occasion requires that they should not be immediately identifiable as someone engaging in such conduct”, but it seems difficult to argue that dealing with protests is such an activity. Breaching the conditions of the licence is an offence under the Private Security Industry Act 2001.

Other plainclothes security were present at the protest. A police sergeant helping coordinate the police operation told DirectReaction that these men had identified themselves as working for Sir Philip Green himself. When she asked them about the two men who had previously been evicting protesters, who were now standing just metres away, Green's team said they did not know who the men were working for, and that they were not part of the same team.

Topshop parent Arcadia has not yet responded to requests to discuss the use of plainclothes security at the protest. We want to ask them who were these men who were clearly employed by someone to help control the protest? If they are licensed security staff, then they appear to have broken the law by failing to display identification. If they weren't, then under what authority were they entitled to eject protesters from the store?

The government can exempt security personnel from the licensing regime if their employers are deemed to have an equivalent set of vetting procedures that protect the public. But if that applies to the men at Topshop, does Green operate some kind of special security unit that has applied to the government for authorisation to avoid being licensed?

The use of plainclothes police to monitor protests has already caused a stir, but there is no reason private security staff should be held to a lesser standard, especially if they are engaged in crowd control. Plainclothes security have already been criticised by photographers for using undue force at earlier UKUncut protests against Vodafone. If they are going to be throwing around protesters, they should be accountable, and that means making sure the public know who they are.