Security has been stepped up at Redbridge Town Hall after lead was stolen from its roof.
The theft from the building in High Road, Ilford, happened in early December.
A spokesman for Redbridge Council said additional security measures have been put in place to prevent repeat offences.
The lead has been replaced with a “substitute” that costs less.
Lead thieves have struck a number of buildings in the area, including St Mary the Virgin Church, also in High Road.
It has had two such thefts in the last year, with �6,000 of lead being stolen on the most recent occasion.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here