Daniel Ricciardo is closer to Lewis Hamilton than perhaps any driver in the Formula One paddock but even the Australian has admitted that the Briton is complex character who is "hard to read".

The two drivers spent time together at the Coachella Music Festival in California earlier this year and, on Thursday, shared jokes off camera during an official press conference to preview Sunday's spectacular night race in Singapore.

This weekend Hamilton starts as the favourite to win his ninth grand prix of the season after setting the pace in practice on Friday. Hamilton is closing in on a remarkable sixth world championship but continues to divide opinion at home.

The 30-year-old Ricciardo was asked why this might be case. "Lewis is cool [but] ... I guess he is complex,” the Renault driver said. “I have always had positive interactions with him, but I am not silly and I can see how people have other opinions. Whether it is his lifestyle, or that sometimes he can be quite reserved and you don’t get much out of him.

“He reached a high level at a young age, and there is the fame that comes with that. He was exposed to the celebrity lifestyle and naturally that can have an effect.