Activist Srisuwan Janya has filed complaints with the National Anti-Corruption Commission (NACC) questioning recent actions of Future Forward Party leader Thanathorn Juangroongruangkit and army chief Apirat Kongsompong.
Mr Srisuwan submitted the complaints with the NACC on Tuesday, saying Mr Thanathorn had appeared to side with the Hong Kong protesters after a picture of him and Hong Kong student activist Joshua Wong was released recently.
Mr Srisuwan, also secretary-general of the Association for the Protection of the Thai Constitution, said the picture had provoked a response from the Chinese embassy in Thailand.
The embassy last Thursday issued a statement accusing a Thai politician, understood to be Mr Thanathorn, of contacting one of the protest groups.
The NACC must finish the probe quickly to prevent the issue straining the bilateral relations, according to Mr Srisuwan.
In a separate complaint, the association secretary-general criticised Gen Apirat for accusing certain academics and politicians of damaging the country and the highest institution.
Gen Apirat said last week in Bangkok that those involved in fomenting domestic unrest cannot function without the support of both local people and allies abroad.
He made the remark during a lecture on national security at the Royal Thai Army Headquarters.
Mr Srisuwan said the army commander should be politically impartial and that his remarks were indicative of his inability to stay neutral.