Italy's supreme court has ordered a retrial for Giuseppe Orsi, the former CEO at Leonardo-Finmeccanica, who was sentenced to four and a half years in April for his alleged role in helicopter contract kickbacks in India.

The decision means the supreme court found procedural errors in the April conviction, and has effectively voided that verdict, requesting a new trial take place.

The charges related to a 560 million euro deal to sell 12 AW101 helicopters to India in 2010, when Orsi was head of Agusta Westland, then a unit of Italy's Finmeccanica, which is now known as Leonardo-Finmeccanica.

The twists and turns of Orsi's legal odyssey since then are symptomatic of Italy's lengthy and often convoluted three stage justice system.

He was first arrested in 2013, alongside Bruno Spagnolini, another former AgustaWestland head, on suspicion of paying bribes to the former Indian air force chief to buy the AW101. Following the arrests, India cancelled the contract.

The two men went to trial, but a year later, an Italian court acquitted Orsi and Spagnolini of international corruption, handing them instead two year sentences for the lesser charge of false book keeping.

Under Italian law, defendants can appeal guilty verdicts, but prosecutors can also appeal against acquittals. An appeal was held, where Orsi's lawyers pushed to overturn the false book keeping sentence handed down at the first trial, while prosecutors argued for the reinstatement of the corruption charges.

The appeal court took the magistrates' side, handing Orsi four and half years and Spagnolini four years in April.

But now, the supreme court, which can order fresh appeal trials if it finds procedural fault at the appeal stage, has done just that.

Italian media reported on Friday that a second appeal trial may however be timed out by the statute of limitations in 2017, meaning the case would remain unresolved by Italian justice, seven years after the crimes were allegedly committed.

In India, the consequences of the probe into Orsi have meanwhile continued.

Last week the former head of the air force S.P. Tyagi, 71, who was accused of receiving kickbacks from Italy, was arrested.