Gjert Ingebrigtsen, the father of Olympic 1500m champion Jakob, has been charged by Norwegian police with physical abuse.
Last year, Jakob, 23, and his older brothers Henrik 33, and Filip, 31, who are also Olympic athletes, made public claims that their father, who had coached them until 2022, had been violent.
The 58-year-old has strenuously denied the allegations.
Police in Norway, who had been investigating the case, said on Monday that Gjert had been charged with one offence.
Norwegian website VG, which published the initial story with the brothers, said the victim, external, who was allegedly beaten with a wet towel on one occasion, was not one of the three siblings but a younger family member.
The remaining cases against Gjert have been dropped – five on the strength of evidence and one because of time constraints.
Mette Yvonne Larsen, who represents five of the Ingebrigtsen children, told VG they would appeal against at least one of the dropped cases.