In an apparent security lapse, a standby passenger in place of a confirmed ticket holder boarded the Varanasi-bound IndiGo flight at the Mumbai airport on Tuesday and was later deboarded before the plane took off.

Generally, an airline staff who can take a flight in case there is a vacant seat is referred to as a standby passenger.

In a statement, IndiGo said there was an error during the passenger boarding process of 6E 6543 from Mumbai to Varanasi, wherein a standby passenger was allotted a seat reserved for a confirmed passenger.

"The error was noticed prior to the departure of the aircraft, and the standby passenger was de-boarded. This led to a slight delay in the departure of the aircraft," the airline said.

Further, IndiGo said it will take all measures to strengthen its operational processes.

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