Christian Michel has been in jail since December 2018 after he was extradited from Dubai.

The Supreme Court said that while the "investigation is still ongoing", Michel must be released on conditions laid down by a lower court.

The Central Bureau of Investigation, India's top investigating agency, has filed three chargesheets in the case.

In January 2014, New Delhi cancelled a deal with Italian-British consortium AgustaWestland -- agreed under a previous government in 2010 -- after allegations the firm paid bribes to win the $677 million contract for 12 helicopters.

Indian investigators charged Michel in 2017, when he was working in the United Arab Emirates, with arranging $52 million as kickbacks.

In 2021, United Nations rights experts accused India of extraditing and jailing Michel in a suspected swap for a Dubai runaway princess.

Sheikha Latifa, the daughter of Dubai's ruler Sheikh Mohammed bin Rashid Al-Maktoum, was captured by Indian commandoes at sea in 2018 after trying to flee the UAE.

Despite a growing arms export market, India has become the world's largest arms importer with purchases steadily rising to account for nearly 10 percent of all imports globally in 2019-23, the Stockholm International Peace Research Institute (SIPRI) said last year.

More is in the pipeline, with orders worth tens of billions of dollars from the United States, France, Israel and Germany in coming years.