Illegal surveillance cameras on road signs

In Seer Green since 22/4 people noticed several partially hidden cameras in various locations. One was attached to the seer green sign where Bottom lane meets longbottom. A 2nd in the trees where bottom lane turns into Orchard Road. A 3rd on a road sign by Gurnells rd - marked on map and also 2 photos of device on that sign. also 2 on lampost at end of Highlands rd and 2more at the corner of orchard rd and wynnswick rd. A couple who live on the corner of bottom lane and orchard rd saw a man up the trees opposite their house and asked what he was doing as they thought the camera was looking into their bedroom. He claimed not to know but said he thought it was a road survey. He had a white transit van with Highways Maintenance on the side. Another resident saw him and said it said surveillance (private and council) on the van. She can't remember the company name but did google at the time and she look online later today to see if she can find the website again. After the cameras were noticed yesterday and raised on our local whatsapp group they have mysteriously disappeared overnight. Someone also noted that there was a similar device on the A40 in middle of duel carriageway near the recycling centre. I did report the cameras to the Police yesterday - ref 712- and have updated them today. I spoke to fix my street and they could find no record of the council doing this. This seems very sinister and I want to know if this surveillance was initiated by the council.