The Delhi police, directed by a Delhi court to probe whether any chargesheet was ever filed in connection with the hijacking of an Indian Airlines plane to Pakistan in 1981, has been asked to submit its final report in the matter by October 10.

Additional Chief Metropolitan Magistrate Kamini Lau also asked the assistant commisioner of police to give four-day notices to the four accused before asking them to join the investigation.

Earlier, the ACP expressed his inabilty to comply with the court's direction to submit the report by May 10 due to some technical impediments and sought more time to hand it in.

He contended that a few aspects related to the hijacking and culpability of the accused under the Indian Penal Code were still to be explored as they had allegedly served life terms in Pakistan for the offence.

Acceding to the ACP's plea, the court on Saturday granted a "last opportunity" to the police for filing its final report.

The accused -- Tejinder Pal Singh, Satnam Singh, Gajender Singh and Jasbeer Singh -- had on September 29, 1981, hijacked IA's Srinagar-bound flight to Lahore after it had taken off from Delhi.

In January 1986, they were sentenced to life imprisonment by a court in Pakistan. They were deported to India in 1997 after serving their sentence.

The fact that they were chargesheeted came to light after Tejinder filed an application in 1997, seeking discharge from the case registered in India on the ground that he had already served a sentence for the crime in Pakistan.

Tejinder contended he could not be prosecuted twice for the same offence under Article 20 of the Constitution.