Thai politicians and business figures are among those being investigated by the country's Anti-Money Laundering Office, but it did not name anyone at a news conference.
The agency's secretary-general, Seehanat Prayoonrat, said the 16 people were listed as directors or shareholders for companies set up by Mossack Fonseca. Leaked documents from the firm that have been published worldwide showed it helped thousands of individuals and companies from around the world set up shell companies and offshore accounts in low-tax havens.
Seehanat said AMLO was seeking confirmation on the Thai names from authorities in Panama.
The agency focuses on money laundering but said it will share its findings with tax, banking and stock market authorities.