A bid to evict travellers from green belt land will be considered at a court hearing next week.
Up to 10 caravans and campervans moved onto the site off the A406, which is owned by Blackhorse Ventures Ltd, a sister company of C&S Builders Merchants Ltd, about a month ago.
Security guards are currently guarding the entrance to the site opposite Sainsbury's in Walthamstow Avenue, behind Waltham Forest Muslim Cemetery.
Manager Mohinder Sumal, of C&S Builders Merchants in Blackhorse Lane, confirmed the company is due in court on Tuesday.
He said: "I understand they've been there for about a month but we were only made aware of them about a week-and-a-half ago."
Mr Sumal said attempts have been made to build on the land, but these had been rejected by Waltham Forest council.
He also said the company will be implementing “heavy curbs” to protect the site in the future.