More than £30,000 worth of metal drain covers have been stolen from the streets of Brent in the last two months, the council has revealed.
A staggering 95 steel grates have disappeared, as opportunist criminals attempt to cash in on the rising value of scrap metal.
It is believed the thieves are selling the covers to scrap metal yards for around £10 each, but the local authority is being forced to fork out £325 for replacements.
Dangerous holes are now popping up across the borough and the council is being forced to cover the health hazards with plywood and cones.
Councillor Daniel Brown, responsible for highways and transportation, said: "The council has already contacted scrap metal yards about the issue and we will be taking a hard line with the thieves responsible.
"We are concerned that people may injure themselves because of these holes. The metal grates are also costly to replace and a waste of taxpayers' money."
The council said it had seen a massive increase in the number of thefts and stated that smaller roads with no CCTV survealiance were being targeted.
A number of other London boroughs have reported a similar trend.
People are being urged by the council to get in touch if they spot drain holes left uncovered or see people working on the road without any displaying official markings on vehicles or clothes.
Residents can also contact their Metropolitan Police Safer Neighbour-hood Team via the police switchboard on 020 7372 1212 or online at www.met.police.uk/brent