The official says the bomb went off on Wednesday as the officer was driving from work in the southern city of Ataq in Shabwa province, once an al-Qaida stronghold.
The official says the explosion, which had all the hallmarks of al-Qaida, also wounded two people. He spoke on condition of anonymity because he was not authorized to speak to the media.
Yemen is fighting a war against al-Qaida's local branch, considered by Washington as one of the world's most dangerous offshoots of the terror network.
The branch has carried out large suicide attacks and assassinations in the past years, including killing two officers in drive-by shootings this week.