The announcement was followed by a press conference in which John Bowmer, the chairman, refused time and time again to answer journalists' questions, citing legal restrictions.

It was revealed that Bowmer has taken over control of the company as executive chairman, leaving group CEO Jerome Caille to manage day-to-day business.

Bowmer, who described himself as 'usually rather garrulous', told more than a hundred journalists of his 'intense frustration' at not being able to answer questions about 'the technical details of what is happening in our audit situation, details of the government investigation, the future, or things that are not yet know with certainty.'

Asked whether either Arrieta or Weber had resigned, he declined to comment, adding 'personnel issues' to the list of off-limits topics. In an earlier press statement, the company thanked both men for their years of service. It named Andres Cano, group financial controller, as interim CFO while the board works on a permanent replacement.