A bench of Chief Justice P Sathasivam and Justice J Chelameswar also accepted a CBI application on modification of a 2010 order upholding its stand to make Salem stand trial for charges under TADA, Explosive Substances Act and Explosives Act.

Salem was extradited from Portugal in 2005 following an assurance by the then Deputy Prime Minister that he would neither be given death penalty nor imprisoned beyond 25 years.

A trial court slapped additional charges on the gangster after he was extradited.

While a Salem challenge to these charges was shot down by the SC in 2010, courts in Portugal held that the extradition was violated, compelling CBI to rush to the apex court again.

Salem opposed the CBI plea and claimed that since the extradition had been repudiated by Portuguese courts, he could not be tried in India anymore.

SC, however, allowed CBI to drop some serious charges in the 1993 Mumbai serial blasts case to save his extradition. It said the offences for which Salem was extradited were grave enough and no prejudice would be caused to any party if the application for modification was allowed.

SC also made it clear the order could not be construed as review of its 2010 judgment in the light of the Portugal Constitutional Court verdict.

"India and Portugal are two sovereign States with efficient and independent judicial systems. The verdict by the Constitutional Court of Portugal is not binding on this Court but only has persuasive value," it said, while also underlining that diplomatic talks were on between the countries over differences in judicial opinions.

The bench also accepted a submission by Attorney General G E Vahanvati that Salem's extradition had not been terminated by Portuguese courts and the final decision rested with the Portuguese government.

SC noted that the Constitutional Court of Portugal had categorically held that Portuguese law did not provide for any specific consequence for violation of the Principle of Speciality (over charges) and their findings might not be construed as a direction to Union of India to return Salem.