Two men have been placed under formal investigation in connection with the theft of Pablo Picasso masterpieces from the Paris flat of the artist's granddaughter.A third man allegedly connected with the case has been released and is being treated as a supervised witness.The three men, aged between 45 and 60, were detained on Tuesday. On Thursday they appeared in a Paris court, with the two under judicial investigation - a first step to formal charges - held in custody.Two paintings and a drawing by the Spanish master were taken from the Left Bank apartment of Diana Widmaier-Picasso as she lay sleeping on February 26.Thieves made off with the 1961 Portrait of Jacqueline, depicting Picasso's second wife, and Maya with Doll, a painting of the artist's daughter from 1938. The stolen drawing was called Marie-Therese at age 21.The suspects are described by police as "professional dealers in stolen goods."It is thought they were planning to sell the Picassos, along with other stolen works, on the European art market.