Police in China say they have found 790,000 fake and duplicate ID records in their system by using image matching technology.
The statement from the Ministry of Public Security on Sunday said the IDs have been nullified and those involved in the forgeries punished. It did not give details.
It also said that any police officers found to have been involved in forging IDs would be fired.
In China, citizens have to register their residency with police.
This gives them access to housing and education benefits and an ID card.
People with multiple IDs can gain access to additional benefits, hide their assets and circumvent property ownership restrictions.
In a high-profile case last year, a former vice president of a rural bank, Gong Ai'Ai, was found to have acquired multiple identities and more than 40 pricey Beijing apartments.
Dubbed ''Sister House,'' she was sentenced to three years' imprisonment for forging and trading official documents.
The official Xinhua News Agency reported that a former police officer was sentenced to one year in prison for helping Gong to obtain the fake IDs.