Hertsmere Borough Council is investigating building work at a new kosher restaurant, after local traders complained it had started without permission.
Kosher chain Mr Baker submitted an application to convert a building on the high street in Borehamwood from a retail site to a restaurant.
Hertsmere Borough Council confirmed it had been received complaints that work had started at the premises.
A spokesperson for the council confirmed that they were looking into the matter and pointed out that, "there is already a planning application in concerning two properties and that is being looked at too.
"We are also in contact with the shop owner over the issue."
David Shamash, of Mr Baker, said: "There has been some recent delay in proceedings. However, we are working hand in hand with the local authority to ensure that all planning and concept details are ironed out."