The committee began its probe last week, but the Editors Association said that in contrast to former parliamentary investigations the process is not as open and transparent as it should be – particularly when it comes to giving information about the witnesses being called to testify before the committee.

Several high-profile figures are expected to testify, but the exact list of witnesses is secret. Opposition politicians have named 200 people they want to question, including current and former government officials in Austria and Bavaria, market watchdogs, and senior central bankers.

Wolfgang Sablatnig, head of the Editors Association, told Ö1 radio that unlike in previous parliamentary hearings there is no official list detailing which witnesses will give testimony on which day, which makes it hard to give the public accurate information about what is going on.

The deputy head of the opposition Greens party, Werner Kogler, had said that most spectacular parts of testimony in the investigation, which could last up to a year, might never emerge given new restrictions on what can be discussed with media present.

Hypo has been given €5.5 billion in state aid since 2008, and has increased deficits and state debt, as well as straining relations with Bavaria, whose BayernLB bank once owned Hypo.

Hypo was nationalized in 2009 after a decade of expansion fuelled by unaffordable debt guarantees from Carinthia.