A Swiss court Friday sentenced jail terms to four members of Britain's richest family for exploiting Indian staff at their Geneva mansion.

The Hindujas, who were not present in court, were acquitted of human trafficking, but convicted on other charges.

The family's fortune is estimated at 37 billion pounds ($47 billion).

Prakash Hinduja and his wife Kamal Hinduja each got four years and six months, while their son Ajay and his wife Namrata received four-year terms, the presiding judge in Geneva ruled.

The cases related to the family's practice of bringing servants from their native India. It included accusations of confiscating their passports once they were flown to Switzerland.

Prosecutors argued the Hindujas paid their staff a pittance and gave them little freedom to leave the house.

The family denied the allegations. It had reportedly reached a confidential out-of-court settlement with the three employees who made the accusations against them.

Despite this, the prosecution decided to pursue the case due to the gravity of the charges.

Geneva prosecutor Yves Bertossa had requested a custodial sentence of five and a half years against Prakash and Kamal Hinduja.

Aged 78 and 75 respectively, both had been absent since the start of the trial for health reasons.

In his closing address, the prosecutor accused the family of abusing the "asymmetrical situation" between a powerful employer and a vulnerable employee to save money.