Mercedes motorsport boss Toto Wolff has warned Lewis Hamilton and Nico Rosberg not to overstep the mark in their growing rivalry.

The relationship between the teammates has deteriorated in recent weeks due to a number of incidents during qualifying and races.

Rosberg was unhappy with Hamilton's decision to turn up the wick on his power unit in Barcelona despite being ordered not to, while the Englishman is understood to have felt that Rosberg deliberately drew yellow flags in order to deny him pole position in this weekend's Monaco Grand Prix.

Hamilton has played down speculation of a rift between him and the German, but Wolff admitted that the two had been at loggerheads over events in recent weeks.

"I can tell you, on the Sunday in Barcelona we had some emotions from [Rosberg], which is understandable. You are in the car, alone out there, you don't have a perspective of what is going on around you. Obviously if you lose out to your team-mate, either in qualifying or in the race, that is a frustrating situation," Wolff told reporters.

"In Barcelona, Nico felt aggrieved by what had happened in the race and I guess this is really normal. Everybody has their own absolute reality, absolute belief. I guess it is like arguing with somebody where you think you are right, the other person thinks he is right, but it is never black and white. There is sometimes grey. Right now I think they are probably exploring how far you can step over the line and what the consequences are. Isn't that normal?

"You have a chance of winning the championship, and as long as it isn't detrimental to the team spirit, as long as it is not underhand, we will handle the situation in the way we did before. But the moment it goes in the direction where we believe it is not in the spirit of Mercedes-Benz we will act accordingly. For instance, what happened with the engine settings, that is never going to happen again."

Rosberg ended Hamilton's run of four consecutive victories with success in Monaco today, leapfrogging his rival at the top of the driver rankings in the process.