GP2 racers Johnny Cecotto Jr. and Julian Leal have both been penalized following Friday's qualifying session in Singapore.
Arden International driver Cecotto was found culpable for hindering championship contender Sam Bird on the approach to Turn 16.
Bird qualified 10th, with title rival Fabio Leimer third fastest, and complained on Twitter: "Well done again Mr Ceccotto!!! [sic] Ruined my qualy again! Should have been p5 at least.... however he had other ideas."
Bird and Cecotto had previously clashed in qualifying in Malaysia.
Stewards also found that Leal had impeded Cecotto approaching Turn 6. Both drivers have been given three-place grid penalties for Saturday's feature race.
Leal will still start in 14th place to Cecotto's 16th.