German Chancellor Angela Merkel's office had repeated contact with Wirecard from late 2018 onwards, a government spokesman confirmed on Wednesday, as questions mount over how much the government knew about the tech firm's dubious accounting practices.

The chancellery in Berlin had several dealings with the now-insolvent Wirecard and its advisors, with former intelligence service commissioner Klaus-Dieter Fritsche and former defense minister Karl-Theodor zu Guttenberg having played a role in arranging meetings, the spokesman told German Press Agency (DPA).

Merkel is under pressure to explain her relationship with Wirecard, which has long faced allegations of financial misconduct and imploded in an embarrassing scandal last month after a 1.9-billion-euro (2.2-billion-dollar) hole emerged in its accounts.

During a trip to China to promote German business interests back in September 2019, Merkel brought up the payment service provider's planned takeover of Chinese company AllScore Financial.

"At the time of the trip, she had no knowledge of possible serious irregularities at Wirecard," the spokesman said, adding that the government regularly promotes the economic interests of German companies during its bilateral meetings with other countries.

At a government press conference later Wednesday, government spokeswoman Ulrike Demmer noted that such promotion overseas is a "completely normal procedure."

Merkel spoke with zu Guttenberg, a Wirecard advisor, ahead of the China visit, during which she was accompanied by a large business delegation, according to information from her government.

On Aug. 13, 2019, Fritsche, whose relationship with Wirecard remains unclear, is said to have contacted the chancellery to ask for a meeting between Wirecard AG and Merkel's business adviser Lars-Hendrik Roeller.

Ahead of this appointment, which took place on Sept. 11, 2019, staffers in the chancellery had called the Finance Ministry in order to gather information on the company.

Finance Minister Olaf Scholz was made aware on Feb. 19, 2019, that Germany's Bafin financial regulator was investigating Wirecard for suspected market manipulation, his ministry has said.

The Bundestag parliament's finance committee is to hold a special hearing on the Wirecard scandal on July 29, during which Scholz and Economy Minister Peter Altmaier are to face questioning.

Opposition parties had also called for Merkel to appear before the committee.

Next week's hearing will take place behind closed doors.