Sir Dave Brailsford is expected to be interviewed as a witness by French police investigating allegations that the Paris Saint-Germain head coach, Christophe Galtier, made racist comments while manager of Nice. A leaked email apparently sent to Brailsford in May 2022 by Julien Fournier, Nice’s then director of football, was published last week and purported to show that Galtier had complained to Fournier in August 2021 that he “could not have so many blacks and Muslims in the team”. Brailsford, the director of sport for Ineos – Nice’s owner, which is in talks to buy Manchester United – was urged to take action against “completely unacceptable, intolerable events, attitudes and comments that are contrary to my values, from the coach”. Galtier left Nice in June 2022 to take over at PSG. The Nice prosecution office announced last week that it had launched a preliminary investigation into “discrimination based on alleged race or religion” and a report in L’Équipe on Wednesday said the Nice president, Jean-Pierre Rivère, is among those to have been questioned by police, with Brailsford also expected to be interviewed “in the next few days”. Brailsford has been asked for comment by the Guardian. On Wednesday, Nice denied reports that players had been instructed not to comment on the allegations against Galtier and insisted the club were co-operating with the police investigation as they prepare to face Basel in the second leg of their Europa Conference League quarter-final at the Allianz Riviera. “There is no ban on self-expression,” a spokesperson told L’Équipe. “This case came out the day before a European match. We asked to focus on this historic moment for the club. Today a judicial investigation is under way, we cannot make any public comment but all those wishing to do so will be able to express themselves within the framework of the procedure.” Galtier has vehemently denied the allegations and said he would be launching legal action against Fournier and the journalists who first reported on the email. “I was stunned by the comments that were attributed to me and that were relayed in an irresponsible manner,” he said last week. PSG said in a statement last week that they would support Galtier – who is expected to depart at the end of the season after the team were eliminated in the last 16 of the Champions League by Bayern Munich – and “wishes that the judicial system will shine a light on the truth on the serious allegations against our coach”.