High Priest Imhotep was mummified alive for which crime in the 1999 Brendan Fraser film "The Mummy"?

Imhotep (Arnold Vosloo) is the title character of the 1999 film "The Mummy". This film has elements set in 1290 BC. Imhotep is High priest under the rule of Pharaoh Seti I. He is having an affair with Pharaoh Seti's mistress, Anck-su-namun. They murder the Pharaoh after he discovers their affair. For his crime, Imhotep is punished by enduring the Curse of Hom Dai, a ritual that involved mummifying him alive, while his sarcophagus is filled with carnivorous scarab beetles.

As a result of the curse, Imhotep is made an undead fiend with control over sand and other elements. Imhotep is defeated when his immortality is taken by the powers of the Book of Amun-Ra. He comes to his end when he is impaled with a scimitar. He decays back into his skeletal mummy form. As he is decaying, he is also falling into the pool from which he summoned Anck-su-namun's soul. He finally mutters "Death is only the beginning" in Ancient Egyptian.

This very popular film was written and directed by Stephen Sommers. It was produced by James Jacks and Sean Daniel. The screenplay was written by Stephen Sommers from story ideas provided by Sommers, Lloyd Fonvielle, and Kevin Jarre. "The Munmy" was distributed by Universal Pictures and grossed $415.9 million US dollars at the box office worldwide. It coast just over $80 million US dollars to make. Because of its box-office success, the picture led to two sequels (2001 and 2008 respectively).