More than £30,000 worth of 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 take advantage of the rising cost 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 pay £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.
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 taxpayer's money."
The council said it has seen a massive increase in the number of thefts and that smaller roads with no CCTV are being targeted.
A number of other London boroughs have reported a surging in the level of drain covers going missing.
The council is now urging people to contact them if they spot uncovered 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 Neighbourhood Team at or via the police switchboard on 0207 372 12 12.