Germany’s finance ministry has come under fire over an attempt to secretly interfere with the questioning of a key witness during a parliamentary inquiry into Wirecard, a potential breach of parliamentary etiquette.

The collapse of the German payments company last summer sent shockwaves through Germany’s financial and political elite. A parliamentary inquiry has exposed multiple regulatory failures and led to the departure of the heads of three supervisory agencies.

Days ahead of Friday’s final parliamentary debate on the committee’s final report, the finance ministry disclosed that one of its senior officials tried to intervene in the inquiry’s work in the run-up to the questioning of Munich chief prosecutor Hildegard Bäumler-Hösl, a key witness.

The government revealed this in a written answer to a question raised by Fabio De Masi, an MP for the hard-left Die Linke party, which was seen by the Financial Times.

The ministerial official was not named, but can be identified by the description of his role, as Reinhard Wolpers, the head of the subdivision financial market stability. Wolpers is one of three finance ministry employees who are members of BaFin’s administrative council. The finance ministry declined to comment on his identity.

In the run-up to the questioning of Bäumler-Hösl in January, Wolpers approached BaFin’s then-vice president, Elisabeth Roegele, and asked her to provide questions for Bäumler-Hösl which he then would pass on to MPs.

The government has no constitutional role in the inquiry, which is being pursued by parliament and has powers akin to a court. Moreover, Roegele was also nominated as a witness and had not yet been questioned by MPs at that point. She was forced out of her job by the government alongside President Felix Hufeld in late January.

“Wolpers’ behaviour is a clear violation of rules,” De Masi told the Financial Times, adding that the government official showed a “lack of respect for the Bundestag”.

BaFin and Munich prosecutors are embroiled in a blame game over the controversial 2019 short selling ban which investors regarded as a vote of confidence in the disgraced company. BaFin imposed the ban after receiving information from Munich prosecutors about an allegedly imminent short selling attack against Wirecard.

Several BaFin employees told MPs that Munich prosecutors had stated that the information was highly credible. Bäumler-Hösl denied that and said she just passed it on to BaFin without commenting about its validity.

The short-selling ban is potentially toxic for German finance minister Olaf Scholz, who is the Social Democrats’ candidate for chancellor in September’s federal election.

The finance ministry scolded the watchdog publicly for the short selling ban, saying it was based on poor and insufficient analysis.

The ministry’s response to De Masi disclosed that Wolpers approached Roegele via email and text messages days ahead of Bäumler-Hösl’s testimony. The ministry said Wolpers “acted upon his own, personal initiative and did not co-ordinate with other employees of the finance ministry”. It added that the executive level “at no point” was informed about the behaviour but only became aware of the matter because of De Masi’s inquiry.

“The communication of [our] employee with Ms Roegele was eventually without a result, as Ms Roegele did not submit such suggestions for questions,” the ministry said, adding that “no information” was passed on to members of the inquiry committee from the ministry.

Lisa Paus, a Green MP, said that the “authority of the finance ministry” was misused for the political interest of the Social Democrats. “That’s an absolute no-go.”

Florian Toncar, an MP for the pro-business Free Democrats, said that it would be “very surprising” if Wolpers’ actions were “not approved or even requested by the ministry’s senior level”.

Jens Zimmermann, SPD representative on the inquiry, said he was unable to comment on internal procedures at the ministry “as I don’t have any insights [into them]”, adding that his only contact was with the ministry’s official representatives in the committee. “I did not receive any suggestions for potential questions to Ms Bäumler-Hösl,” Zimmermann said.

Wolpers and Roegele did not respond to FT requests for comment. Munich prosecutors declined to comment.