Six police officers face homicide charges in a Swiss court case that opens on Monday following the 2018 death of a Black man from a heart attack after he was pinned, face-down, for several minutes during arrest.

The officers, whom Reuters did not name due to Swiss privacy laws, face charges of "homicide by neglect" in the case of Mike Ben Peter, a 39-year-old Nigerian man before a Lausanne criminal court. They all contest the charges and will seek acquittal, their lawyers said.

The case, which has some similarities with the May 2020 killing of George Floyd in the United States, is one of four where Black men have died during police interventions in Vaud canton since 2016. They have sparked protests and calls for reforms.

But unlike Floyd's killing, for which officer Derek Chauvin was convicted of murder in 2021 partly based on cellphone footage showing him kneeling on the victim's neck, there is no footage of the incident that allegedly contributed to Ben Peter's death.

A group of U.N. experts said last year Switzerland has systemic racism issues in a report that raised serious concerns about "excessive use of force and the expectation of impunity by police" and cited this case. A government-mandated study released since admitted the problem was structural and said measures had so far been insufficient.

Simon Ntah, the lawyer for the family, said he was not hopeful for a ruling against the officers who face a maximum prison sentence of three years. "As long as there isn't a mechanism for independent investigations against the police we are stuck with the same problems," he told Reuters, complaining how the same public prosecutor who works with police on other criminal cases is placed in charge of cases like this one.

The public prosecutor's office declined to comment.

The indictment showed that Ben Peter drew the attention of officers during a Lausanne drug patrol after he collected a bag later shown to contain marijuana.

He did not comply with police requests and the officers used pepper spray and knee kicks to the ribs and crotch to handcuff him on the ground, it showed. He continued to struggle as he was held face-down by several officers for 3 minutes, it said, until they noticed he appeared unconscious.

Ben Peter was later pronounced dead after a heart attack with multiple causes, the indictment said, including the fact that he was held on his stomach and subjected to stress but also his obesity.