The Federal Board of Revenue on Wednesday froze the bank accounts of Pakistan International Airlines for failing to pay taxes worth billions, sources said.

The national flag carrier is due to pay around Rs4.5 billion in taxes while it has also failed to file tax returns since February of the ongoing year, they added.

Meanwhile, the Pakistan State Oil (PSO) has also demanded the immediate payment of Rs1.5 billion from the PIA and threatened to stop supplying fuel to its airplanes over non-payment of dues.

The airline has accumulated billions of dollars in losses and liabilities, which the caretaker government says it can no longer fund and had been in dispute with the PSO over payments.

In September, the PSO said that “to further support the national carrier” it had extended the credit facility by Rs500 million ($1.82 million). It added the PIA’s outstanding balance to the PSO was Rs26.8 billion ($97.37 million).

The PSO had earlier suspended the credit facility, and the PIA had been paying Rs100 million against daily purchase of fuel.

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It is the second time in five months that the FBR froze the accounts of the PIA after the airline failed to pay its taxes.

In July this year, FBR sources said that PIA owes Rs4 billion in taxes which had already been collected from customers as Federal Excise Duty but was never handed over the tax body.