The filing of the appeal assumes significance as Attorney General K K Venugopal had recently advised the agency against moving a petition against the high court verdict after a delay of 12 years.
Sources, however, said that after consultations, law officers were in favour of the appeal as the CBI came out with 'some important documents and evidence' to challenge the high court order.
The agency swung into action after the Attorney General orally gave it a go ahead to file the appeal in the case in which it has cited the October 2017 interview of private detective Michael Hershman, who alleged that the then Rajiv Gandhi-led Congress government had sabotaged his investigation.
Hershman, who is the president of the United States-based private detective firm Fairfax, had claimed in television interviews that Rajiv Gandhi was 'furious' when he had found a Swiss bank account 'Mont Blanc'.
He had also alleged that the bribe money of the Bofors gun scandal had been parked in the Swiss account.
Sources said that the CBI in its appeal stated that further investigation was necessary in view of the reports relating to Hershman's interviews.
Further in the petition, the agency said that the high court erred in quashing the case by ignoring the evidence it collected through letters rogatory from foreign country which was to be dealt by the trial court.
It said the high court quashed the proceedings in an arbitrary manner saying that the documentary evidence obtained by the CBI from authorities in Sweden were 'neither available in original nor as duly authenticated copies'.
The Central Bureau of Investigation filed the appeal against the May 31, 2005 decision of the high court by which all accused, including Europe-based industrialists Hinduja brothers, were discharged from the Rs 64-crore pay-off case.
The agency will urge the apex court to condone the delay in filing the appeal by contending that 'crime never dies and lapse of time should not come in the way to proceed against offenders howsoever powerful they may be'.
Earlier, the attorney general had advised the CBI to make out a case as a respondent in the petition filed by Bharatiya Janata Party leader Ajay Agarwal, who had challenged the 2005 high court order after the agency had failed to file a special leave petition (appeal) within the mandatory limitation period of 90 days.
Agrawal, who contested the 2014 Lok Sabha election from Rae Bareli against the then Congress president Sonia Gandhi, has been pursuing the case for over a decade in the apex court which on the last hearing on January 16 had asked him to prove his locus in the case as a third party.
The CBI in the case was represented by Additional Solicitor General Maninder Singh.
During the brief hearing on December 1, 2016, the agency had told the apex court that the authorities had not permitted it to immediately file an appeal against the May 31, 2005 verdict.
The appeal, sources said has mentioned that the permission not granted by the UPA-1 government in 2005 to move the apex court 'jeopardised national and public interest' as 'perpetrators are yet to be brought to book'.
Sources said the agency has considered the views of investigating officers associated with the case since 1986.
After the high court had quashed the case, they had studied the judgement and gave an 'unanimous recommendation' that 'an SLP should be filed in the Supreme Court to set aside the May 31, 2005 order of the high court'.
The investigating officers were of the opinion that a prayer should be made in the apex court for 'restoration of the case from the point immediately after the framing of charges in the trial court (March 26, 2004)'.
In the SLP, an advocate of the Centre, closely associated with the case, said the CBI has also raised objections to a 'superfluous remark' of Justice R S Sodhi (since retired) who while quashing the case said that the investigation had caused the exchequer nearly Rs 250 crore.
However, later on an RTI application filed by Agrawal, the CBI had said that it had spent nearly Rs 5 crore on investigation in the Bofors case.
Justice Sodhi (since retired) of the Delhi high court on May 31, 2005, had quashed the CBI case in the Bofors pay-off scam.
Before this, another judge of the high court, retired Justice J D Kapoor, had on February 4, 2004, exonerated late prime minister Rajiv Gandhi in the case and directed the framing of charge of forgery under section 465 of the Indian Penal Code against Bofors company.
The Rs 1,437-crore deal between India and Swedish arms manufacturer AB Bofors for the supply of 400 155mm howitzer guns for the Indian Army was entered into on March 24, 1986.
Swedish Radio on April 16, 1987, had claimed that the company had paid bribes to top Indian politicians and defence personnel.
The CBI on January 22, 1990 had registered the first information report for alleged offences of criminal conspiracy, cheating and forgery under the IPC and other sections of the Prevention of Corruption Act against Martin Ardbo, the then president of AB Bofors, alleged middleman Win Chadda and the Hinduja brothers.
It had alleged that certain public servants and private persons in India and abroad had entered into a criminal conspiracy between 1982 and 1987 in pursuance of which the offences of bribery, corruption, cheating and forgery were committed.
The first charge sheet in the case was filed on October 22, 1999, against Chadda, Ottavio Quattrocchi, the then defence secretary S K Bhatnagar, Ardbo and the Bofors company.
A supplementary charge sheet was filed against the Hinduja brothers -- S P Hinduja, G P Hinduja and P P Hinduja -- on October 9, 2000.
A special CBI court in Delhi on March 4, 2011, had discharged Quattrocchi from the case saying the country could not afford to spend hard-earned money on his extradition which had already cost Rs 250 crore.
Quattrocchi, who had fled from here on July 29-30, 1993, never appeared before any court in India to face prosecution.
He passed away on July 13, 2013. The other accused persons who died are Bhatnagar, Chadda and Ardbo.
Fake Chinese-made parts supplied for indigenised Bofors guns: CBI
Why the Bofors scandal CANNOT be forgotten
Bofors is an OLD story retold
'B' for Bofors, 'N' for Nobody?
Army's new howitzer damaged while firing Indian ammunition