Sri Lanka's national airline on Tuesday blamed a rat for grounding a plane for three days, sparking chaotic delays and fears it will scare off investors for the cash-strapped carrier.

The stowaway rodent was spotted enjoying the SriLankan Airlines Airbus A330 flight from the Pakistani city of Lahore on Thursday, triggering an aircraft search to ensure it had not chewed through critical components.

An airline official said the plane has now resumed flights, but that the grounding had a knock-on effect on the entire schedule.

"The aircraft was grounded for three days at Colombo," an airline official said, declining to be named. "The plane could not be flown without making sure that the rat was accounted for. It was found dead."

The state-owned airline, which had accumulated losses of more than $1.8 billion at the end of March 2023, has three other aircraft grounded for over a year out of a fleet of 23.

The carrier has no foreign exchange to pay for mandatory overhauling of the engines.

Aviation minister Nimal Siripala de Silva told reporters the errant rodent might scare off "the few investors" interested in taking over the debt-burdened airline.

Successive governments have attempted to sell it without success. A previous government offered the airline for one dollar, but there were no takers.

The International Monetary Fund, which bailed out Sri Lanka last year with a $2.9 billion loan spread over four years, has stressed that such state-owned enterprises are a heavy burden on the national budget.

The airline was profitable until a management agreement with Emirates was scrapped in 2008, following a dispute with then-president Mahinda Rajapaksa.

The carrier had refused to bump fare-paying passengers and give their seats to 35 members of Rajapaksa's family, who were returning from a holiday in London.

Ironically, one of the airline's most profitable years was in 2001, when the Tamil Tigers separatist movement destroyed several aircraft in an attack -- with the insurance payouts and the removal of excess capacity boosting its income.