New Delhi: The Supreme Court Thursday asked the CBI to come up with very strong grounds against the discharge of Kerala Chief Minister Pinarayi Vijayan and two others in the SNC Lavalin graft case, as the high court as well as the lower court have held that they should not be tried in the matter.

The CBI said this is a cross appeals matter filed in 2017 and it will file a comprehensive note giving the factual aspect of the matter.

A bench of Justices U U Lalit, Vineet Saran and S Ravindra Bhat was told by Solicitor General Tushar Mehta, appearing for the CBI, that this is an appeal against the discharge of the accused in the case of alleged corruption in awarding contract to the Canadian firm when Vijayan was power minister in 1996 allegedly causing a loss of Rs 374.50 crore to the state exchequer.

He said the trial court had initially discharged some accused in the case and the Kerala High Court had upheld the decision.

The bench said, since two courts have concurrently held that certain accused should not be tried in the case, you (CBI) have to come up with very strong grounds to shake that finding in the matter.

Mehta said that initially a PIL was filed in the Kerala High Court on which it ordered a CBI probe in the case.

He said that CBI filed the charge sheet in the case in 2009 but some of the accused were discharged by the trial court in 2013, a decision which was later upheld by the High Court in 2017.

The bench summarising the arguments of Mehta said that the CBI has filed the appeal against discharge of the accused, while some other accused who were not discharged have filed the appeal in the top court against the high court order for their discharge.

As per the CBI charge sheet, there were 11 accused in the case. The trial court discharged six of them but the High Court upheld the discharge of only three accused.

The three accused have moved the top court seeking their discharge, while five others are facing the trial.

Mehta said that since the matter is old, he would like to file a detailed note giving the timeline of the events and factual aspect of the matter.

The bench granted liberty to CBI to file a comprehensive report on factual aspects of the matter and listed the matter for further hearing on October 16.

On August 23, 2017, the Kerala High Court had upheld the discharge of Vijayan in the SNC Lavalin graft case, saying the CBI had "wrongly picked" him as prima facie there was no case against him.

The high court had also upheld the discharge of two others in the Rs 374.50-crore graft case while rejecting the CBI's plea that their full-fledged trial was necessary to prove the conspiracy.

The high court's verdict had come in a revision petition filed by the CBI in 2014 challenging the discharge of Vijayan and five others in the case by a special CBI court in Thiruvananthapuram.

The CBI special court, Thiruvananthapuram, had in November 2013 discharged Vijayan and others in the case.

The CBI, which had filed the charge sheet in the case, had argued that there was sufficient evidence to prove the charges against the accused.

The discharge by the special court was 'illegal', CBI had stated in its revision petition.

The special judge had ruled that the CBI had failed to prove the charges of conspiracy and corruption levelled against Vijayan and other accused.

The CBI had argued before the high court that a trial was must to prove the conspiracy in giving the contract to revamp the power projects to the Canadian firm when Vijayan was power minister in 1996.

Claiming that the conspiracy was hatched at different stages in awarding the contract, the CBI had assailed the lower court order discharging Vijayan and six others and said a full-fledged trial was necessary to prove the conspiracy.