New Delhi: The Supreme Court on Thursday asked the CBI to look into the allegation of "unnecessary" purchase of 111 aircrafts and leasing of some other by Air India between 2004 and 2008 when the Congress-led UPA was in office costing Rs 67,000 crore to the exchequer.

The allegations, made by NGO Centre for Public Interest Litigation, include allotment of bilateral routes to private airlines at the expense of the national carrier.

The allegations by the CPIL also include an aborted order for the porches of biometric passenger identification system allegedly at an inflated price.

Nationalist Congress Party leader Praful Patel was the Civil Aviation Minister when the aircraft were purchased and taken on lease.

Noting that most of the allegations in the petition by the CPIL have resulted in adverse comments by the CAG/PAC, the bench of Chief Justice Jagdish Singh Khehar, Justice N.V. Ramana and Justice D.Y. Chandrachud said: "... the CBI shall take into consideration all the allegations made in the pleadings of the instant petition, and take a call thereon, based on the evidence collected."

The CBI is already investigating into the allegations and had registered case on February 27, 2013.

Having asked the CBI to look into the allegations, the court in its order said: "As and when the final determination is rendered, whether to initiate criminal proceedings or otherwise, it shall be open to the aggrieved party (if any), to take recourse to the remedies available to it, in consonance with law."

Disposing of the PIL, the court said: "We hope and expect, that the CBI will adhere to the time frame indicated to us, namely, June, 2017.

Opposing the plea by the CPIL, Attorney General Mukul Rohatgi told the court that most of the allegations made in the PIL have resulted in adverse comments by the CAG and later by the Public Accounts Committee in 2014 which was then headed by the BJP's Murli Manohar Joshi.

He also informed the court that following adverse observations by the PAC, the Ministry of Civil Aviation has submitted a detailed response on January 19, 2015. The Ministry on May 3, 2016 gave further response in wake of more queries from the PAC.

The court was informed that the PAC report was proposed to be laid before the Parliament in its winter session which ended in logjam on account protests by opposition on demonetisations.

The counsel for the petitioner organisation CPIL had sought a court monitored probe. But Chief Justice Khehar said one could understand the plea if the same government was there.

"When the government is different, (the) party in power is different... We must have faith in our investigating agency," he said.