NEW DELHI (AFP) - India's top judge said on Monday that the Italian ambassador cannot claim diplomatic immunity in a growing dispute over two Italian marines who skipped bail while on trial for murder.

Chief Justice Altamas Kabir said Daniele Mancini, who had negotiated the marines' release last month so they could vote in Italy's election, had waived his immunity by giving an undertaking to a court that the pair would return.

"A person who comes to court and gives an undertaking has no immunity," Chief Justice Kabir told a hearing into the case, which has caused a diplomatic crisis between Rome and New Delhi.

Massimiliano Latorre and Salvatore Girone, who are accused of murdering two Indian fishermen last year, had been given permission to fly to Italy to cast their votes on the understanding that they would return.

But the Italian government announced last week that it would renege on its commitment to send the men back, prompting fury in New Delhi.

The Indian government has warned of "consequences" and is reviewing its ties with Italy, while the Supreme Court ordered that Mr Mancini should remain in the country and explain himself in court on Monday.

Mr Mancini's lawyer argued that the diplomat enjoyed immunity in line with international rules which also guarantee foreign representatives freedom of movement. But he pledged that his client would stay in the country.

"We have lost all trust in the ambassador," replied Chief Justice Kabir, who was heading a three-judge bench.

India's foreign minstry has also argued that Mr Mancini may have waived his immunity by willingly submitting himself to the jurisdiction of the Supreme Court by signing a personal affidavit guaranteeing the return of the marines.

Without legal protection, he could be prosecuted for contempt of court.

The next hearing in the case was set for April 2.

The marines face murder charges in India after shooting dead two fishermen off India's southwestern coast in February last year when a fishing boat sailed close to the Italian oil tanker they were guarding.

They say they mistook the fishermen for pirates.

Italy insists the marines should be prosecuted in their home country because the shootings involved an Italian-flagged vessel in international waters, but India says the killings took place in waters under its jurisdiction.

Relations between the two countries have also been soured by corruption allegations surrounding a US$748 million (S$936million) deal for the purchase of 12 Italian helicopters which the Indian government is now threatening to scrap.