Residents had to be evacuated from their homes as the Explosive Ordnance Disposal unit disposed of the suspicious package.
David Gunson, 73, from Hailsham was found with serious injuries on a verge on the A22 at around 4.38am on Friday 21st September.
Investigators found what they believe to be a "large-scale" operation in a warehouse in Hailsham. Officers arrested three men.