Yingluck Shinawatra has complained about being followed by people whom she believes were plainclothes police and authorities during her family trip.
The former prime minister, who is on vacation during the New Year's holidays with her son, said she never expected companions from authorities.
"I never thought I would be closely followed by plainclothes police and authorities, who also checked on the shops and places I visited," Ms Yingluck wrote on her Facebook page on Tuesday.
"Government resources should be better spent on looking after the people, not on following me," she wrote.
Ms Yingluck did not specify the places where she claimed she had been followed but her earlier posts in social media showed she was at a resort in Pai district, Mae Hong Son province, on Monday.
There has been no reaction from authorities after her complaint, which drew more than 700 comments, most of them from her sympathisers and Facebook followers.
"Why did they have to do this?" a supporter commented.
They were violating her privacy, another wrote.