Nearly 4,000 people are having an affair in Sunderland

The index, from the dating website Illicitencounters.com, claims to show the number of people cheating in a local area based on their user numbers and population.

Sunderland is ranked 50 out of 52 cities in the United Kingdom with 3,836 people cheating on their partners in the city meaning 0.37 per cent of the capital city's people are being unfaithful.

It is one of the best cities for monogamy, with Newcastle ranked tenth in the list, only below Durham in the percentage of cheaters.

Most cheaters in England

Out of the bigger cities in England, St Albans has the most cheaters compared to population size according to the website, with 5,631, or 2.74 per cent, of residents in the city reportedly cheating.

This ranks top of all UK cities.

Durham is also worse than Sheffield with 5,650 residents, or 2.4 per cent of people being unfaithful.

Those living in Newcastle are not far behind with 21,074, or 1.91 per cent of residents cheating on their partners.

Durham the best place for cheaters in North

Windsor in Berkshire has the highest proportion of cheaters in the United Kingdom, with Beverley in East Yorkshire the highest northern town in eighth with 3.11 per cent of its population cheating.

The most faithful town in England for the monogamous amongst us is Bournemouth where only 0.17 per cent of people are unfaithful.