World champion Lewis Hamilton destroyed a hospitality room after crashing in Baku qualifying.
F1 legend and Mercedes team chairman Niki Lauda made the revelation on Austrian television Servus TV, also claiming Hamilton "lied" about having a good relationship with Nico Rosberg.
"The more Rosberg is in front, the wilder Lewis gets," Lauda said, according to Speed Week.
"I was there when he smashed his room in Baku because he had hit the wall. Of course he paid for the damage himself."
As for Hamilton’s supposed lie, Lauda said that what Hamilton told the media recently about his relationship with Rosberg was obviously not true.
"He lied. To say it was all ok with Nico was just for show," he said.