Calvey and five colleagues have been in custody since February on allegations of embezzlement involving a Russian bank where Calvey's firm, Baring Vostok, has a controlling stake. They all deny wrongdoing.
Calvey's arrest sent shockwaves through the Moscow business community, as he had avoided political controversy and helped develop Russian tech companies. A French colleague of Calvey, Philippe Delpal, had his custody period prolonged Tuesday.
Baring Vostok has said the case results from a dispute between shareholders at a Russian bank and maintains its staff acted legally.