Four members of the UK’s richest family are on trial in Switzerland amid allegations they spent more money caring for their dog than their servants.

The Hinduja family, worth an estimated £37bn ($47bn), is accused of exploitation and human trafficking.

The family own a villa in Geneva’s wealthy neighbourhood of Cologny, and the charges against them all relate to their practice of importing servants from India to look after their children and household.

It’s alleged that Prakash and Kamal Hinduja, together with their son Ajay and his wife Namrata, confiscated staff passports, paid them as little as $8 (£7) for 18-hour days, and allowed them little freedom to leave the house.

Although a financial settlement over exploitation was reached last week, the Hindujas remain on trial for trafficking, which is a serious criminal offence in Switzerland. They deny the charges.

This week in court, one of Geneva’s most famous prosecutors, Yves Bertossa, compared the almost $10,000 a year he claimed the family had spent on their dog, to the daily amount they were allegedly paying their servants.

The Hinduja family’s lawyers did not specifically deny the allegations of low wages, but said they must be viewed in context – noting that the staff were also receiving accommodation and food.

The charge of long hours was also disputed, with one defence lawyer arguing that watching a film with the Hinduja children could not really be classed as work.

Some former servants testified for the Hindujas, describing them as a friendly family who treated their servants with dignity.

But the allegations that servants’ passports were confiscated, and that they could not even leave the house without permission, are serious, because they could be judged as human trafficking.

Mr Bertossa is calling for prison terms, and millions of dollars in compensation as well as legal fees.

It is not the first time that Geneva, a hub for international organisations as well as the world’s wealthy, has been in the spotlight over the alleged mistreatment of servants.

In 2008, Hannibal Gaddafi, son of Libya’s former dictator Muammar Gaddafi, was arrested in his five star Geneva hotel by police acting on information that he and his wife had been beating their servants, including with a coat hanger. The case was later dropped.

But it caused a huge diplomatic row between Switzerland and Libya, with two Swiss citizens arrested in Tripoli as a retaliatory measure.

Just last year, four domestic workers from the Philippines launched a case against one of Geneva’s diplomatic missions to the United Nations, claiming they had not been paid for years.

The Hinduja’s ongoing, high profile case will draw attention, once again, to the darker, uglier side of the city that likes to call itself “the city of peace”.