French authorities have detained four additional people in connection with last month's audacious jewelry theft at the Louvre Museum, though the fate of the stolen treasures remains unknown.

Paris prosecutor Laure Beccuau said two men, aged 38 and 39, and two women, aged 31 and 40, all from Paris, were held for questioning. Investigators provided no update on whether any of the jewels, valued at an estimated $102 million, have been recovered.

The investigation has raised serious questions about museum security. Thieves reportedly used a forklift to smash a window and enter the Apollo Gallery in broad daylight, completing the robbery in just seven minutes.

Earlier this month, four other suspects (three men aged 35, 36 and 39, and a 37-year-old woman) were charged with organized robbery and accessory to organized robbery. Many of the stolen pieces, including items that belonged to Empress Marie Louise and other French royals, are believed to have been dismantled or altered quickly to avoid detection.