Sauber has reiterated that its major new partnership with several Russian companies is still on course, and slammed "falsehoods and rumours" in the media.
Reports in the German press on Tuesday claimed that the deal was in jeopardy, suggesting that the involvement of the NIAT (National Institute for Aviation and Technology) in particular was in doubt.
But in a statement issued to AUTOSPORT, Sauber insisted that the reports were inaccurate.
It said the NIAT's role was never intended to be financial but that funding was already forthcoming from other elements of the Russian partnership.
"Our announced co-operation with Russian partners is on a solid footing," it said.
"The contract with driver Sergey Sirotkin is active, and he will commence preparations next week - after Formula 1's obligatory holidays.
"In addition contracted payments to the team have already been made.
"A financial contribution from NIAT (National Institute for Aviation and Technology) was never planned - a technical cooperation forms the basis of our contract with NIAT, and this is ongoing.
"We are bewildered by the ease with which various media have published falsehoods and rumours."