This was a black and white movie I saw as a child in the early to mid 1960 s. I remember that there were 2 men transporting it(the mummy) somewhere in the rear of a panel van,this van had wooden slats over a small semi oval shaped window that was behind them. The mummy had curved claws and broke through the slats to grab the driver by the throat and kill him,I believe it also killed the passenger as well. The van wrecked and the mummy was thrown free. Police came and investigated the scene and saw the mummy and the dead van drivers. When they looked again,the mummy was gone. A later scene I remember was that the mummy was cornered in a barn and holding jewels in its hand that had been left in a hay manger . I have been searching for this for many years as it scared me half to death when I was little. I want to see it again as an adult.