The office of Tunisia's president has received a letter containing suspicious powder and is investigating the matter, a source there told Reuters on Wednesday.
President Kais Saied did not open the letter and is in good health, the source said, Reuters reports.
Some local websites reported that the lethal toxin ricin had been found in the envelope, and that it had been addressed to the presidency in the Carthage Palace.
The source in the office declined to comment on the reports.
Factional tensions have been growing within the government, amid protests against widespread unemployment and social inequality.