Mamata Banerjee on Monday said her flight could have had a mid-air collision with another aircraft, which had come tantalisingly close to the chartered plane on which she had been flying back from Varanasi on Friday after campaigning for Akhilesh Yadav for the Uttar Pradesh polls.

The Bengal chief minister heaped praises on the pilot for averting a mid-air collision.

“Another airplane had come in front of ours. In ten more seconds, there would have been a head-on collision. We were saved because of the pilot. He dropped the flight by 8,000ft,” Mamata told journalists at the Assembly.

Her aircraft made a sudden descent of a few thousand feet in the air. The drop was made minutes before the plane was supposed to touch down at the Calcutta airport. The incident reportedly injured her, a source had said on Friday.

Immediately after the touchdown, the directorate general of civil aviation had claimed that the aircraft had faced a turbulence caused by weather issues.

Mamata on Monday swatted away the DGCA theory and claimed that her security personnel had the graphs, which record the descent made by the airplane. She added that there had been no report on the “flight descend” from the airport authority so far.

Calcutta airport officials denied that there was any aircraft close to the plane carrying Mamata on Friday.

A source said investigations had revealed so far that the Dassault Falcon aircraft hired by the state government was 25 nautical miles northwest of Calcutta on its way to the city from Varanasi.

“The nearest aircraft was four nautical miles or 7km from the chief minister’s aircraft. There were no other aircraft in between these two planes,” said an airport official.

The DGCA is conducting a probe and its officials reached Calcutta on Monday, said sources. The state home secretary had sent a letter to the airport director seeking a probe. The airport director has forwarded it to the DGCA, said officials.

Repeated incidents of trouble faced by Mamata’s flights prompted the Trinamul Congress’s mouthpiece Jaago Bangla to question the true reason behind such episodes.

Earlier in 2016, Mamata’s flight from Patna to Calcutta had to circle for half an hour in the air before it was permitted to land. The state government ordered a probe into the matter. It was alleged that even after the pilot had complained to the ATC that the flight was running out of fuel, it was not allowed to make a touchdown.

In 2017, a flight carrying the chief minister from Delhi to Calcutta was delayed by four hours. Again in 2018, Mamata’s flight from Bagdogra to Calcutta waited for a long time in the air before it could land since there was no runway empty.