(Bloomberg) -- Executives at one of China’s largest copper trading houses have lost contact with the company’s founder and believe that he has been detained by police for questioning, according to people familiar with the matter.Most Read from BloombergIsrael Latest: Top US General Warns Iran to Stay Out of ConflictSchumer Confronts Xi on Israel-Hamas Stance in Rare MeetingIsrael Latest: Over 1,100 Dead; US Sends Warships to RegionBank of America’s Wrong-Way Rate Bet Hurts Moynihan’s Growth Pled