SINGAPORE—China blocked Wells Fargo banker Chenyue Mao from leaving the country because she is required to assist in a criminal probe, China’s Foreign Ministry said Monday, marking Beijing’s first confirmation of the exit ban.

A Wells Fargo banker has been blocked from leaving China due to a criminal matter, the country's foreign ministry has confirmed.

China's foreign ministry said on Monday Chenyue Mao, the Wells Fargo banker who has been blocked from leaving the country, was involved in a criminal case and was obliged to cooperate with the investigation.