Some staff of India's national airline Air India have been found stealing alcohol and caviar from flights, the aviation minister said in parliament.
The airline's vigilance department is also probing reports that a pilot took 22m rupees ($404,800; £254,191) in flying allowances even when he was grounded for medical reasons.
The cash-strapped airline has been making heavy losses for several years.
Its pilots have been on strike for 10 days amid a row over training schedule.
The vigilance department is investigating 161 such cases dating back several years, Civil Aviation Minister Ajit Singh said in a written statement in the parliament.
In one case, a flight purser was caught by the customs department while taking 372 mini liquor bottles from a plane.
In another incident, a catering officer was found with 20,200 rupees ($371; £233) worth of caviar taken from a chartered flight.
The statement said in one case, a pilot was found flying for another airline while still on Air India's payrolls.
A spokesperson for the Indian Pilots' Guild confirmed to the BBC that there had been incidents of pilfering by some staff.
He also confirmed that some pilots were found guilty of malpractices but "no action was taken against them".
Ten days ago, about 200 Air India pilots collectively called in sick - forcing the airline to cancel a number of international flights from Mumbai and Delhi.
Estimates say the strike is costing the airline more than 10m rupees ($183,644; 115,550) a day.
Last month, the government approved a $6bn (£3.8) bailout package for the debt strapped airline.