CATALYTIC converters worth a total of £6,000 have been stolen from vans.
The thefts happened on Peterlee’s North West Industrial Estate between Saturday and Monday, when the parts were taken from the Mercedes Sprinter vans.
The vehicles were being hired out to two separate firms, with two vehicles at each site.
The company which owns the vans, which has asked not to be named, is offering a £200 reward for information which leads to a charge of the crimes.
It is believed the convertors, each valued at £1,500, could have been stolen by metal thieves.
Anyone with information is asked to call 0345 60 60 365.