Randy Blythe, frontman of US heavy metal group Lamb of God, pleaded not guilty in court in Prague on Monday on the first day his trial on involuntary manslaughter charges for the 2010 death of a fan.

The singer also told a municipal court in the Czech capital he wanted neither to escape responsibility nor be punished for something he did not do, local media reported.

Blythe, 41, is on trial for pushing a 19-year-old fan off the stage onto a concrete floor during a concert at a Prague club in May 2010.

He could face up to 10 years behind bars if convicted. The fan's family is asking for 10 million koruna (389,000 euros, $527,000) in damages.

In court on Monday, Blythe admitted to having pushed the young man off the stage, but said he then saw him stand up in the crowd.

The fan, who repeatedly tried to climb on to the stage according to news reports, died of head injuries two weeks later.

A post-mortem reportedly found that he had not been drunk or under the influence of drugs.

"The prosecution has qualified the act as battery resulting in death. The defence definitely does not see it as such," Blythe's lawyer Vladimir Jablonsky told AFP earlier.

Czech police detained Blythe upon his arrival at Prague airport in June 2012.

He was freed without charge in August but had to post 237,000 euros bail, then left the country, vowing to return for the trial.

Lamb of God have scored a 2013 Grammy nomination for the best hard rock/metal performance with their song "Ghost Walking".