Lewis Hamilton on Wednesday said Formula One is facing a "pivotal moment" as it battles a series of off-track controversies early in the new season.

The build-up to last weekend's season-opening Bahrain Grand Prix was overshadowed by the fall-out caused by Red Bull's investigation into alleged inappropriate behaviour by its team boss Christian Horner.

On Tuesday, motorsport's governing body the FIA said its compliance department was "assessing" reports that its president Mohammed Ben Sulayem told officials not to certify the track used for last year's Las Vegas Grand Prix.

"It doesn't look good from the outside and it doesn't look good from within," seven-time world champion Hamilton told reporters ahead of this week's Saudi Arabian Grand Prix.

"I think it's a really important time for the sport to show and to stick to their values, holding ourselves accountable for our actions.

"It's a pivotal moment in terms of what we project to the world and how it's handled -– and it's not been handled very well to this point.

"Transparency is really key. I am hoping to see some progress moving forward, but I hope it is not a year that continues to go on like this, but it does highlight some of the issues we have within the sport."

A BBC report earlier this week also said a whistleblower claimed Ben Sulayem intervened at last year's Saudi race, when George Russell was briefly promoted to third after Fernando Alonso was penalised because his team touched his car during a penalty pit-stop.

The penalty was then withdrawn in a review process allegedly influenced by Ben Sulayem and Alonso reinstated in third place.

"We want to see all of the facts and just have total transparency really," said Russell.

"We're all racing here. We all want a fair and level playing field for us to showcase what we can do."

Alonso suggested that the story had resurfaced because Red Bull's domination on the track was less interesting than the off-track intrigue that has also focused on potential internal problems at Red Bull.

Reigning world champion Max Verstappen's father, Jos Verstappen, said last weekend that Red Bull will "explode" if Horner remains in charge of the team.

"There is too much talk off the track because on the track is not very exciting," said Alonso.

"There is one car winning for the last 72 grands prix, more or less dominating for three years."