President Tayyip Erdogan said Turkey's armed forces have never used chemical weapons and that legal action would be taken against those who make such allegations, broadcaster NTV reported on Friday.
Media close to the Kurdistan Workers Party (PKK) militant group published videos this week which it said showed chemical weapons being used by the Turkish army against the PKK in northern Iraq.
"Our armed forces have not resorted to using chemical weapons to this day," NTV quoted Erdogan as telling reporters on his plane returning from a trip to Azerbaijan.
The defence ministry and top officials on Thursday also denied the armed forces had used chemical weapons in their operations against Kurdish militants.
Turkish prosecutors on Thursday opened an investigation into the head of the Turkish Medical Association, Sebnem Korur Fincanci, after she said on television that footage indicated the use of toxic gases and called for an independent investigation.
State-owned Anadolu news agency said Financi was accused of "making terrorist group propaganda" and "denigrating the Turkish nation, the Republic of Turkey and its institutions".
An international medical federation published a report this month seeking independent investigation of possible violations of the 1997 Chemical Weapons Convention by the Turkish military.
The PKK is designated a terrorist group by Turkey, the European Union and United States. More than 40,000 people have been killed in fallout from the insurgency that it launched against the Turkish state in 1984.
(Reporting by Ece Toksabay; Writing by Daren Butler; Editing by Ali Kucukgocmen and Nick Macfie)
