A journalist who had seen one of the leaflets contacted respected Wiccan high priest and Pagan Federation member Mani Navasothy, who assured the reporter that pagans "don’t do animal sacrifices and definitely not people".
You can read the story the journalist wrote about the situation here: http://www.guardian-series.co.uk/news/efnews/9834622.EPPING_FOREST__Pagans_deny__ridiculous__abduction_claims/
I would like to add that not only would modern pagans never commit animal or human sacrifice, pagans are also very responsible about caring for the environment and would not light barbecues, campfires or bonfires in places where fires are banned. And anyone sneaking into Epping Forest in the hope of spotting naked witches cavorting in the woods is likely to be very disappointed.
For journalists wanting to investigate this situation further, I would recommend reading these guidelines on how not to spread misinformation about the occult: http://www.badwitch.co.uk/2012/04/news-how-not-to-spread-misinformation.html
Here are some ideas of things pagans might do to celebrate Lammas: http://www.badwitch.co.uk/2009/07/doing-your-own-thing-for-lammas.html