http://en.espnf1.com/f1/motorsport/story/160127.html
However, Wolff revealed that the tension dates back to the epic battle between the two in Bahrain where Rosberg was using engine modes that Hamilton was not and then Hamilton did the same when the pair were racing in Spain in two weeks ago. Wolff played down the significance of the two incidents, but said it had added to the tension in Monaco and would not be allowed in the future.
"In the last couple of races we had some little fouls left and right, and in the team we made sure this is not happening again," Wolff said. "The most obvious bit is you can play around with the engine modes, so this is not happening ever again.