SINGAPORE: The McLaren team has hinted that rivals Red Bull had used coded messages to assist Australian Daniel Ricciardo's drive to a podium finish in Sunday's Singapore Grand Prix.

McLaren's racing director Eric Boullier said he and his McLaren colleagues had listened keenly to other teams' messages during the race.

Daniel Ricciardo's Red Bull car had reliability issues during the Singapore Grand Prix. Credit:Getty Images

Asked how different it was to work on the pit wall following the clampdown on radio communications, he said: "Nothing, but it makes us more busy listening to the others to see they are not doing anything like Red Bull did twice on Ricciardo.

"I think it was coded, yes. It is up to the FIA to investigate, so it is not for me to say anything.