Three Chelsea supporters were spoken to by police after officers received reports of antisemitic chanting on a train carrying fans after the club’s game at Brighton on Sunday.

The development is a fresh blow to Chelsea after a series of alleged incidents related to racism and antisemitism involving their supporters in the space of eight days.

Reports of the chanting came three days after the club strongly criticised fans for singing an antisemitic song during a Europa League game at Vidi in Hungary. Chelsea immediately described the activity as “abhorrent” and questioned the “brainpower” of those responsible.

Before the game at Brighton the Chelsea chairman, Bruce Buck, greeted away supporters and made it clear to those with whom he spoke that this was an important day for Chelsea’s image, with the world watching after the recent controversies.

“Officers received reports of antisemitic chanting on board a train … at around 4pm yesterday afternoon,” a British Transport Police statement said. “BTP attended and three men were spoken to by officers, but at this time no one has come forward to make a complaint.”

Unless a complaint is made police will not be able to investigate. Some Chelsea fans are understood to have reacted to the chants and attempted to stop them being sung.

In Hungary a small number of travelling supporters were photographed outside a bar in Budapest carrying a Chelsea Headhunters flag which featured a Nazi symbol.

The previous Saturday Manchester City’s Raheem Sterling was allegedly racially abused, with four supporters suspended by Chelsea pending further investigations.