New Delhi: Pilots of three Indian flights, who lied to air traffic controllers about being short on fuel to get priority landing , have been suspended .

According to an investigation by the country’s aviation safety regulator, Pilots of three flights, including one operated by market leader IndiGo, lied to air traffic controllers about being short on fuel to get priority landing at an airport.

The incident occurred on Nov. 30, when pilots of an IndiGo plane radioed traffic controllers at Kolkata airport the jet was running out of fuel and it should be allowed to land, bypassing more than half a dozen aircraft waiting in queue. An Air India Ltd. aircraft, ahead of IndiGo, also claimed the same after listening to the conversation, while another plane operated by SpiceJet Ltd. also followed suit, the investigation showed.

None of the aircraft ran the risk of an empty tank, and all of them had enough jet fuel to fly to an alternative airport and attempt at least two landings, or to circle around Kolkata for half an hour, a senior official at the Directorate General of Civil Aviation told reporters in New Delhi, asking not to be identified citing rules.

The pilots of the three aircraft were being “naughty,” and posed a serious threat to preparations when an actual incident of fuel shortage occurs, the official said.

The IndiGo aircraft was carrying Mamata Banerjee, the chief minister of West Bengal state, whose political party raised the issue in parliament, saying her life was threatened, Bloomberg reported.

 SpiceJet denied the regulator’s charges and said their pilots did not seek priority landing or claim that the aircraft was low on fuel. IndiGo, operated by InterGlobe Aviation Ltd., declined to comment while Air India didn’t immediately respond to an e-mail seeking comment. Two calls to Derek O’Brien, spokesman of Banerjee’s Trinamool Congress Party, went unanswered.

The DGCA is cracking down on safety violations by airlines in recent months, including a slew of offenses such as aircraft getting too close to each other, overworked staff and inebriated pilots and crew. The US Federal Aviation Administration downgraded India’s aviation safety rating in 2014 before restoring it a year later following some corrective measures.