The thief has so far targeted 20 vehicles, mainly in the College Road area, since the spree began on Thursday last week.

Sgt Christine Turner, of Ripon Police, said: “I think they know what they are doing and what they after. I presume they sell them but we just don’t know.

“It’s mainly high value German cars such as Mercedes and BMWs. The first one was in College Road but they have been in the Ure Bank area and as far as Magdalens Road.

She added: “It’s purely the glass - they are detaching it from the wing mirror and taking it away and we don’t know why they are doing it.

“It’s an odd thing to take, and so many.”

Sgt Turner said 10 thefts were reported on Saturday morning alone and added the crimes were similar to a spate which occurred in Harrogate two months ago.

Police are calling for vigilance and have asked any suspicious activity to be reported to them on 0845 60 60 247.