Horner was cleared last week by an independent investigation into allegations of misconduct made by a female employee.

The inquiry dominated the pre-season and Horner has remained in the spotlight after an email from an anonymous sender, purporting to contain evidence submitted to the investigation, was distributed to media and key figures in the sport.

"There is tension here while he remains in position," former F1 racer Jos Verstappen told the British newspaper at the Bahrain Grand Prix, where his son dominated Saturday's season-opening race.

"The team is in danger of being torn apart. It can't go on the way it is. It will explode. He is playing the victim, when he is the one causing the problems."

Horner could not be contacted immediately, with Verstappen's comments appearing at around 01:00 on Sunday local time in Bahrain, and a team spokesman did not respond to a query.

Asked after the race about the email, Horner told reporters he would not comment "on what motives whatever person may have for doing this.

"I have the support of an incredible family, of an incredible wife, of an incredible team and everybody within that team and my focus is on going racing and winning races and doing the best that I can."

Verstappen senior also denied involvement in the anonymous email.

"That wouldn't make sense. Why would I do that when Max is doing so well here?" he said.

Verstappen has won the last three championships in a row and Saturday's victory was the 55th of his career, all of them with Red Bull.