Ischinger dismissed the reports, first published by Der Spiegel magazine, to German media as the conference got under way.

Spiegel reported on Thursday that a consulting firm Ischinger co-founded in 2015 sold appointments with officials and contacts for high-level attendees of the MSC on the sidelines of the event.

It said Ischinger had placed his 30-percent stake in the firm in a trust but was still drawing revenue from its activities.

Peter Conze of anti-corruption watchdog Transparency International told the Der Tagesspiegel daily that while Ischinger's activities were legal they "raise questions and could influence the reputation" of the event.

Ischinger, 75, a former German ambassador to the United States and Britain, has run the annual MSC since 2008.

He told public broadcaster Bayerischer Rundfunk Friday that the Spiegel report was "completely outlandish", saying he had "personally never profited" from the MSC.

Running the conference had turned into "an absolutely full-time job", Ischinger said, for which he was reimbursed for his expenses but didn't draw a salary.

He noted that the conference was a private event funded in part with donations and that he had thus sought sponsors, including arms manufacturers, each of whom provided less than 10 percent of the funding.

In exchange, the sponsors were afforded "networking" opportunities at the event with prominent guests.

Speakers this year include US Vice President Kamala Harris and Secretary of State Antony Blinken.

The reports did not cite names of officials to whom companies were offered access.

Ischinger is this year to hand off the leadership of the conference to Christoph Heusgen, a longtime advisor of former chancellor Angela Merkel and former German envoy to the UN.