Thursday 2 February at 06:35 : Feb.2 (GMM) McLaren on Wednesday stopped Lewis Hamilton from responding to former friend Adrian Sutil's "coward" accusation.

Sutil, the 2008 world champion's former F3 teammate, has been Hamilton's closest friend in the paddock throughout their subsequent formula one careers.

But the German slammed his British rival for being "not a man" this week after Hamilton declined to appear as a witness at Sutil's assault trial in Munich.

Despite sitting alongside Sutil in the Shanghai nightclub last April, Hamilton claimed in a written statement to the court he could not remember the details of the alleged assault on Lotus team executive Eric Lux.

"I do not want to be friends with someone like that," Sutil, referring to Hamilton, said after receiving a 18-month suspended jail term and EUR 200,000 fine for grievous bodily harm.

A reporter asked Hamilton about Sutil's anger following the launch on Wednesday of the 2012 McLaren car.

Before the Briton could answer, a McLaren spokesman intervened: "We've been told that Lewis shouldn't really go there because it (the conviction) might go under appeal.

"So can we move on to the next question," he added.

Hamilton told the reporter: "I'll listen to him."

The winner of 17 grands prix had a tumultuous season on and off the track in 2011 but on Wednesday thanked McLaren for granting him a long winter break that left him feeling "fresh" for the new year.

"What I have decided to do this year is just focus on the most important thing and that's racing," said Hamilton.

He also hopes to quickly ease rumours about his expiring McLaren contract.

"I think probably after the first couple of races it's something we will probably want to get out of the way so we can focus on the rest of the year without the team being concerned and without it being something that's just hanging around for us.

"Then you guys won't be having to ask questions about it," he smiled to reporters.