Just Eat has removed 35 restaurants from its app after discovering they were not registered to receive food hygiene ratings.
The food delivery platform has said it is rare to find an unregistered business but that as soon as it is alerted to suspicions, companies are removed from the app while an investigation is carried out.
BBC Inside Out East has revealed that one of the listed firms that did not have a rating was registered to a car wash in Basildon, with no evidence of the site having been used for any other purpose for at least two years.
The food hygiene rating scheme, operated by local authorities, is compulsory for restaurants.
Just Eat has confirmed that it removed the restaurants following a nine month audit, which commenced in November 2016.
A Just Eat spokesperson said: "We take food safety extremely seriously and actively work to raise standards across the takeaway sector.
"Any restaurant wishing to partner with us must be FSA registered with the relevant local authority, and provide evidence of this, before we put them on our platform. Local authorities are then responsible for carrying out inspections to check businesses meet the requirements of food hygiene law.
"We positively incentivise food safety and make numerous resources available to our restaurant partners to support and improve standards in this area, such as dedicated online training and a partnership with NSF, the leading global Food Safety consultants, offering various packages to our partners including having a qualified auditor coming into their business to help improve standards.
"The FSA has welcomed the efforts Just Eat are making to protect consumers and are working closely with us to ensure we can contribute to their current reform programme, Regulating Our Future (ROF), which is modernising the way all types of food businesses are regulated."
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