belize passport no. needs notarization

dear:
i am holding belize passport, i bought one apartment in China in 2008, using my 1st passport, now (2015) i want to sell the apartment, but I hv renewed my belize passport in 2011, so the 1st passport number is different with the 2nd passport, then the china real asset authority officer told me it can not be approved that the 1st pp and the 2nd pp are the same person, the two pp numbers does not link to each other! they told me i should get a proof letter from belize authority government, translate into chinese version, then go the china embassy for notraization, please kindly let me know which china embassy i should contact with? as belize and PRC has no diplomatic relationship yet, thanks for ur help.