Query for marriage in China

Presentlymy son is working in China as a doctor in some medical research program. He wants to marry a Chinese girl. I have obtained the Notorised Affidavit of Single Certificate and a Certificate from Local Government (union Council) in Karachi Pakistan. Both certificates have been verified by the Ministry of Foreign Affairs Pakistan.

Do I need to complete the Application for Authentication of Notarisation form at the local Chinese Consulate in Karachi and submit it to them for authentication.

K.Masood