According to French newspaper L'Equipe, Leeds look set to sign Marseille striker Chapuis on loan until the end of the season.
Chapuis joined Marseille in January 2002 and has scored four times in 42 league games.
He arrived in Leeds on Saturday night and is expected to complete his medical on Sunday, the newspaper added.
Olembe, 22, will also be joined by Brazilian international Roque Junior if he wins his appeal for a work permit tomorrow.
Junior, who was in Brazil's World Cup squad last summer, has agreed terms to join Leeds on loan from AC Milan for the rest of the season.