Formula One driver Adrian Sutil has called fellow racer Lewis Hamilton a “coward” and said he no longer regarded him as a friend for failing to appear as a witness in his trial on an assault charge.

Sutil was on Tuesday given an 18-month prison sentence suspended for three years by a court in Munich after being convicted of causing bodily harm in a nightclub dispute.

Sutil and Hamilton, who have been friends on the Formula One circuit for years, were together at the Shanghai club following the Chinese Grand Prix last April when a row broke out in which Eric Lux, co-owner of the former Renault-Lotus team, was injured.

But former world champion Hamilton did not give evidence in the trial on Monday and Tuesday. Instead, the Briton provided a written statement to say he did not see the incident.

“Lewis is a coward, I don’t want to be friends with someone like that,” Sutil was quoted as saying by Germany’s Bild daily on Wednesday.

The 29-year-old German said Hamilton was “not a man,” adding that “even his father sent me an SMS wishing me luck” for the court case but “from Lewis there was nothing.”

Sutil was also fined 200,000 euros ($A247,500) for the attack in which Lux suffered a gash to the neck which needed stitches.

Sutil’s Formula One future remains open after losing his place at Force India. He is without a team for 2012 and his manager, Manfred Zimmermann, was quoted by Bild as saying a drive this year was now “almost ruled out.”