Top officials in the city of Shenzhen will have to keep their spouses and families in China if they want to keep their jobs.

"Officials whose spouse and children have all emigrated to foreign countries should not take top positions in the Party and government," said a regulation issued by the Communist Party of China (CPC) Shenzhen committee and the Shenzhen government on Wednesday.

Shenzhen's regulation, containing 20 specific requirements for local top officials, is the first substantive enactment that restricts local officials' power and sets clear boundaries, media reports have said.