On Monday, the company backtracked, a day after the JC reported the letter and the anger it had caused locally.
"We apologise for the letter sent to some of our customers asking them to remove religious items from their property, specifically their Mezuzahs," a company spokesperson told the JC.
"The letter was overzealous in its nature and not in keeping with our business values... We wish to make it very clear that residents of the block in question are not required to remove their Mezuzahs and they will certainly not be removed by Warwick Estates or any representatives working on our behalf.
Warwick Estates said the letter was sent "by the property manager who was attempting to perform his job in line with his interpretation of the lease".
They added the company was "deeply sorry for any offence we have caused to the residents at the development and indeed the wider Jewish community".
The spokesperson said: "We thank the members of the Jewish community for bringing the matter to our attention and we will ensure that appropriate training takes place so mistakes such as this do not reoccur again."