MONTREUX, Switzerland, March 24 (Reuters) - Four members of a French family died in the Swiss resort of Montreux on Thursday, and a fifth is in a serious condition, after they fell from the 7th floor of their apartment building, police said.

The Vaud cantonal police said they were still investigating, but have ruled out there being another person in the apartment.

Police said officers had gone to the apartment with a warrant for the father related to the home-schooling of one of the two children.

Officers returned later after a witness notified them that people had fallen from a balcony, police said.

"Five members of the same family fell ... from the balcony of their apartment in Montreux located on the 7th floor of a building on the street of the casino. A man, two women and a young girl died and an adolescent has been hospitalized in serious condition," the police statement said.

The father, aged 40, his wife and her twin sister, 41, and the 8-year-old girl died, while the couple's 15-year-old son survived, it said, adding that formal identification was under way.

(Reporting by Denis Balibouse; Writing by Stephanie Nebehay Editing by Alison Williams)