Sutil was left outraged after Hamilton did not testify at the 29-year-old German's trial this week, with Hamilton's lawyer informing the court his client was unavailable due to a prior engagement with McLaren.
That prompted Sutil to speak out after being given an 18-month suspended sentence and fined 200,000 euros (£167,000) by Munich district court judge Christiane Thiemann.
Sutil was found guilty of causing grievous bodily harm to Eric Lux, chief executive of Lotus team owners Genii Capital.
The former Force India driver was accused of striking Lux with a champagne glass at a Shanghai nightclub after last April's Chinese Grand Prix, causing a neck wound which required 24 stitches.
Speaking to German newspaper Bild, Sutil said: "Lewis is a coward. I do not want to be friends with someone like that. He is for me no man.
"Even his father sent me a text message and wished me luck for the process. Lewis came with nothing. He has changed his phone number. I could not reach him any more."
Asked about Sutil's remarks following today's launch of the new McLaren ahead of the new season, Hamilton was not given an opportunity to reply.
A McLaren spokesperson intervened and said: "We've been told Lewis shouldn't really go there because it might go under appeal, so can we move on to the next question", to which the 27-year-old Hamilton added: "I'll listen to him."