Restaurants were targeted as part of an ongoing campaign to tackle national minimum wage breaches, with employers found to potentially owe staff more than £300 in unpaid wages.

One employee was found to be potentially working for just £4.18 per hour in the joint clampdown by HM Revenue and Customs, police, Home Office and council representatives – including trading standards and environmental health.

Super Ocakbasi Restaurant, in Stoke Newington Road – which won the Best Takeaway in London at the British Kebab Awards in January – was one of six restaurants visited on Tuesday last week.

Although no minimum wage breaches were found, it was issued with an emergency prohibition notice after officials claimed it had a “severe cockroach infestation and dirty work surfaces and equipment.”

The hearing for the notice took place on Thursday last week and was unopposed.

Environmental health officers advised the restaurant owners to perform extensive cleaning on the premises before it could reopen and to call pest control to tackle the cockroach problem.

A spokesman for the restaurant said this week: “We are serving food again; we cleaned everything up and they checked. We were closed for three days but now we are open again.”

The operation also found one business did not have efficient ventilation and needed to ensure better cleaning practices. Another didn’t have a pest control report that was up to date, two businesses were not VAT registered and another wasn’t registered for PAYE.

Deputy Mayor of Hackney, Cllr Sophie Linden, said: “We already know the majority of businesses are good businesses, paying at least the national minimum wage.

“It is the small minority that exploit their staff that we are determined to find.

“In Hackney we want all businesses to go one step further and pay their staff the London living wage and help make it a fair pay borough.”

Employers not paying at least the national minimum wage could be fined, find themselves having to backdate pay to an employee and end up in court.

Anyone aged 21 and over should receive the national minimum wage of £6.50 per hour. For under 21s the wage is £5.13, and under 18s £3.79. Different rules apply to apprenticeships.