Mercedes have called in the police after an anonymous email purporting to be from an insider accused the Formula One team of sabotaging their departing seven times world champion Lewis Hamilton.
Speaking at a Spanish Grand Prix news conference on Friday, Mercedes F1 principal Toto Wolff denied the email had come from anyone within the team, blamed online "cowards" and said the response would be to "go in full force".
"We have the police enquiring it, we are researching the IP address, we are researching the phone, all of that because online abuse in that way needs to stop," he said.
"People can't hide behind their phones or their computers and abuse teams or drivers in a way like this. I don't know what some of the conspiracy theorists and lunatics think out there."
Hamilton, the most successful F1 driver of all time, is leaving Mercedes for Ferrari at the end of the season and has beaten team mate George Russell only twice in nine races since that announcement.
Some of his fans have blamed Mercedes, who are based in Britain, on social media.
The email was received by Formula One's leading figures and permanently accredited media after Russell finished third in the Canadian Grand Prix on June 9.
That was the team's first podium of the season, and Hamilton finished fourth.
Headlined "a potential death warrant for Lewis", it accused Mercedes of "systematic sabotaging" of Hamilton, his car, tyre and race strategy and mental health.
Hamilton said on Thursday he had not seen the email and called for "support, not negativity". He also defended Russell from online abuse.
Wolff, accused in the email of being vindictive and acting "like a scorned wife", told reporters the perpetrator should "get a shrink".
He said Hamilton had been part of the team for 12 years, that he and the Briton were friends and trusted each other while Mercedes also needed both cars fighting for constructors' championship points.
"We're going to end this on a high, we want to celebrate the relationship," he said.
"We want to be successful with the most iconic driver the sport has ever had...I totally respect the reasons for him going to Ferrari, there is no grudge, no bad feeling."
Ferrari boss Fred Vasseur, sitting alongside Wolff at Barcelona's Circuit de Catalunya, concurred.
"How you could imagine that a company with 1,500 people working night and day, pushing like hell to bring upgrades each race, we could damage one of our cars? This is completely irrational," he said.
"Nobody in the paddock could do something like this."