Ahmad said a police raid he led on a wedding ceremony last week in the eastern city of Faisalabad was a major breakthrough in the investigation.
He said a man and a woman from China and a fake priest were arrested at the ceremony, where a Christian girl was to be married.
"The gang members confessed that they have sent at least 36 Pakistani girls to China, where they are being used for prostitution," he said. The majority were Christians from different districts in eastern Punjab province, he said.