SAKHIR (AFP) -- Three-time world champion Max Verstappen gave his struggling rivals little hope for optimism ahead of the new Formula One season when he dominated the first day of winter testing on Wednesday, Feb. 21.

The Red Bull driver was more than a second faster than Lando Norris in a McLaren with Carlos Sainz, about to start his final year as a Ferrari driver, in third spot at the Sakhir track where the season-opener takes place on March 2.

Sainz will lose his seat at Ferrari to seven-time world champion Lewis Hamilton who is entering his last campaign behind the wheel of a Mercedes. Hamilton will be in action on Thursday, Feb. 22.

Verstappen's performance was a boost for a Red Bull team reeling from an investigation into team chief Christian Horner who has been accused of "inappropriate behavior" by a female member of staff.

"It feels good to be back in an F1 car again and I had fun out on track today. We covered a lot of laps and tried quite a few things with the car, which was important, so happy overall with how it went," said Verstappen.

Horner faced questioning for eight hours at an internal hearing in London earlier in February after allegations emerged in the Dutch press of a complaint being made against the 50-year-old Englishman by a female employee.

Horner categorically denies the accusation while Formula One chiefs said they want the issue resolved at the "earliest opportunity".

Mercedes team chief Toto Wolff described the investigation as "an issue for all of Formula One".

"Red Bull has started as an independent investigation, if this is done in the right way with transparency and with rigor, I think that's something that we need to look at -- what the outcomes are and what it means for Formula One, and how we can learn from that," Wolff told a news conference.

"We want to talk about racing cars and we want to talk about the sport rather than these kind of very critical topics, that are more just a team's issue, it's a phenomenon or it's an issue for all of Formula One and in general for every individual that works out there."

Horner is scheduled to appear at a press conference in Bahrain on Thursday.

At the launch of this season's Red Bull car held last week, he insisted he had no intention of resigning.

"No. It's business as usual," he said. "There obviously is a process.

"Obviously, I fully deny any accusations that have been made against me but of course I'll work with that process, which I hope is concluded in the near future."

Testing times on the first day of three on Wednesday:

1. Max Verstappen (NED/Red Bull) 1:31.344 sec (143 laps, 2. Lando Norris (GBR/McLaren) +1.140 (73), 3. Carlos Sainz (ESP/Ferrari) +1.240 (69), 4. Daniel Ricciardo (AUS/Racing Bulls) +1.255 (52), 5. Pierre Gasly (FRA/Alpine) +1.461 (61), 6. Lance Stroll (CAN/Aston Martin) +1.663 (54), 7. Charles Leclerc (MON/Ferrari) +1.903 (64), 8. Fernando Alonso (ESP/Aston Martin) +2.041 (77), 9. Oscar Piastri (AUS/McLaren) +2.314 (57), 10. Zhou Guanyu (CHN/Sauber) +2.527 (63), 11. Logan Sargeant (USA/Williams) +2.538 (21), 12. George Russell (GBR/Mercedes) +2.765 (122), 13. Yuki Tsunoda (JPN/Racing Bulls) +2.792 (64), 14. Valtteri Bottas (FIN/Sauber) +3.087 (68), 15. Alex Albon (THA/Williams) +3.243 (40), 16. Esteban Ocon (FRA/Alpine) +3.333 (60), 17. Kevin Magnussen (DEN/Haas) +4.348 (66), 18. Nico Hulkenberg (GER/Haas) +4.562 (82)