British Airways owner International Airlines group is to appeal a record £183 million fine imposed by the Information Commissioner’s Office following a major data breach last year.

IAG said today: “It is British Airways’ intention to vigorously defend itself in this matter, including using all available appeal routes should they be required.”

The theft of customer data from the BA website was disclosed on September 6, 2018 and October 25, 2018.

IAG said in today’s half year results announcement that it “has not been proven” the airline failed to comply with its obligations under General Data Protection Regulation and the UK Data Protection Act.

IAG reported that its revenues rose 7.9% to €12 billion in the first six months of its financial year.

But pre-tax profits fell by 41% year-on-year to €1 billion.

IAG chief executive Willie Walsh said: “Despite fuel cost headwinds, we delivered a good performance.”

Referring to the second quarter performance, he added: “At constant currency, fuel unit costs were up 6.3% while passenger unit revenue increased 1.1%, benefitting from the timing of Easter.

“This highlights, once again, that our unique structure and diverse brand portfolio underpins our financial resilience and ability to deliver robust results.”

Looking forward, IAG said it expects its 2019 operating profit before exceptional items to be in line with last year at current fuel prices and exchange rates.

More: BA faces multi-million pound lawsuit on top of possible data breach fine