Soilfix encountered the archeological remains on the Rainham site while carrying out remediation and enabling works.
Several trenches it excavated during Autumn 2018 revealed features of interest including possible prehistoric remains and pottery dating from Roman times.
Part of the 3ha site will now be subject to a controlled site strip under the watch of the project archaeologist, and the findings will be recorded and reported in a manner agreed by Archaeology Collective and Historic England
"Our client has taken the responsible decision to stand down all other intrusive works until archaeological recording has been completed to the satisfaction of Historic England and LB Havering," the company says.
"Once completed Soilfix can continue remediation and our client can get building."