A couple of thousand ravers were given the secret location for one of the annual highlights of the free party scene – the Easter bank holiday weekend Eggtek event.

The sun was shining and they arrived at a field on Ministry of Defence land in Lulworth, Dorset in a state of high excitement about a weekend of dancing to techno music playing from a variety of different stages and sound systems in the heart of the countryside.

They knew that police were likely to arrive and intervene at some point because raves are illegal under the Criminal Justice and Public Order Act, which prohibits gatherings of more than 20 people on open land where the music played consists wholly or predominantly of “a succession of repetitive beats”. But they hoped to get a day or two of partying in before being moved on.

What happened next is disputed by police and ravers.

Police say the ravers threw plastic bottles and drink cans at them and that their response to being assailed by these “missiles” using officers with batons, riot shields, dogs and pepper spray was proportionate.