Mercedes chairman Niki Lauda has provided some insight into the tense relationship between current Formula One champion Nico Rosberg and Lewis Hamilton last season.
In what was a grueling and hard-fought 2016 season for the Mercedes pair, the Drivers' Championship went down to the wire as both battled it out in the final race in Abu Dhabi.
Eventually, Rosberg did just enough to clinch the title as well as announcing his retirement from the sport shortly after.
During the race, and the season for that matter, the fierce rivalry between the two competitors was on full display as Hamilton tried to back the German onto the on-rushing drivers.
Lauda revealed the extent of the rivalry in an interview with Graham Bensinger, saying: "They had no relation, which is always bad.
"They were so bad that they didn't even say hello in the morning. I don't expect them to have breakfast together if they don't like each other.
"I don't expect them to sit down and have breakfast, but the relationship was really bad. It affected Lewis mainly and Nico [as well], so it was fine but not easy."
The 2016 Spanish GP provided a telling flashpoint in the season which saw Hamilton and Rosberg collide.
Lauda was quick to call for a team meeting following the incident and was clear in blaming the Brit for the accident.
"The big question was whose fault was it?" Lauda said.
"For me it was clear because Lewis was too aggressive going to the right, hit the grass, couldn't stop his car and then hit him off.
"I said if I have to choose between the two it's more Lewis' fault than Nico's fault. And Lewis did not appreciate that, because he was of a different opinion. He said, 'Why do you criticize me?' I said, 'Excuse me.
"I cannot accept that you guys crash and then we have nothing and nobody's fault. For me it has to be somebody's fault.' And then Lewis really got upset. Nico said, 'Yes, it was your part too, you moved to the inside. Why did you not leave room?' He said, 'Why should I, I was doing the race'."
Lauda reportedly met with Hamilton in Ibiza in order to clarify the situation and the rules set forth, while Mercedes imposed stricter rules of engagement to its drivers.
The new rules came with the possibility of a driver being released if he does not abide by the terms.
The racing legend added: "We put some regulations in, we told them -- especially in Barcelona when the pushed each other off the track -- we said this was unacceptable for Mercedes and one of you guys has to win [the race] you cannot push each other off.
"We had some rules put in, that you are not allowed to [do that] and you have to pay a penalty if you do it again or we will think of releasing you from your contract, because we are team players here and we cannot destroy each other.
"This was the thing. Toto came up with some good rules and we had peace again. We fought hard and the accidents got reduced between them."