Renault chief Jean-Michel Jalinier warned that some of the French marque's F1 customers could soon have their turbo V6s turned off.
May 10 (GMM) Lotus has been left isolated after supplier Renault complained about unpaid engine bills.
Earlier in Barcelona, Renault chief Jean-Michel Jalinier warned that some of the French marque's F1 customers could soon have their turbo V6s turned off.
Jalinier did not name the delinquent teams, but Lotus' struggle to pay drivers and suppliers in 2013 was widely known.
Red Bull is Renault's de-facto 'works' team, so it is unlikely Jalinier was referring to the reigning world champions.
And the boss of the other Red Bull-owned team, Toro Rosso's Franz Tost, said on Friday: "As far as I'm aware, we have paid everything."
The only other Renault-powered teams in 2014 are Lotus and backmarker Caterham.
Caterham team boss Cyril Abiteboul said: "It's a confidential issue but I'm happy since I'm on time to say that we are settled with invoices with Renault Sport F1."
Lotus is yet to comment.