Dentists Rajesh Talwar (front centre) and wife Nupur (back centre, in shawl) are taken to a court in Ghaziabad on the outskirts of New Delhi.

Dentists Rajesh Talwar (front centre) and wife Nupur (back centre, in shawl) are taken to a court in Ghaziabad on the outskirts of New Delhi. Photo: Reuters

An Indian dentist couple were sentenced to life in prison on Tuesday for slitting the throats of their teenage daughter and servant in a case that transfixed the nation, a lawyer said.

A judge handed the sentence to Rajesh and Nupur Talwar who were earlier convicted of murdering Aarushi, 14, and Nepalese servant Hemraj Banjade at their home in an affluent New Delhi suburb in 2008.

"It's life," independent lawyer Naresh Yadav told a scrum of reporters outside the court in Ghaziabad, a satellite city just outside the capital.

Guilty: Rajesh Talwar and his wife Nupur.

Guilty: Rajesh Talwar and his wife Nupur. Photo: AP

Judge Shyam Lal spared the couple the death penalty, which had been sought by the prosecution after their conviction on Monday.

The sentence was the latest dramatic twist in the long-running case that has been awash with sexual rumour and charges of police bungling and media bias.

Investigators allege the Talwars killed Aarushi in a fit of rage after finding her with the 45-year-old domestic servant in an "objectionable position", suggesting the double-murder was a so-called honour killing.

The couple – middle-class dentists – have vowed to appeal, insisting that they are victims of police incompetence and a media witchhunt.

Aarushi was found on her bed with her throat cut one morning in May 2008.

Police initially blamed the missing servant Hemraj – only to find his decomposing body on the roof a day later with a similar cut and head wounds.