Renault on Friday said it is losing patience with some of its F1 team customers.
The French supplier's F1 chief Jean-Michel Jalinier revealed to reporters in Barcelona that more than one partner team is late in paying for its turbo V6 engines.
"I must say we are not at an acceptable situation, because some of the teams are just late in payments, and at the time you need to spend resources to catch up you cannot afford to have those (late) payments," Reuters quoted him as saying.
Renault supplies four F1 teams with engines this year: world champions Red Bull and sister team Toro Rosso, as well as Lotus and Caterham.
It is known that Lotus fell behind in its payments to drivers and suppliers last year, while Caterham and Renault recently scrapped a joint programme to develop road cars.
Jalinier, however, did not name the late-paying customers.
He said Renault would put up with the situation "up to a certain point", but indicated that a final deadline to pay up was looming just "weeks away".
Asked if cutting off the teams' engine supplies was possible, Jalinier said: "That is an option. You first need to work with your team and get back to some kind of financial situation."