Turkish national Omer Guney died at a hospital in Paris on Saturday following a brain illness, one month before his trial was set to take place.

Guney was the only suspect in a murder case dating back to 2013, in which three female Kurdish activists were found shot dead in a neighborhood in the French capital.

The three victims were Fidan Dogan, 28, Leyla Soylemez, 24, and Sakine Cansiz, one of the founders of the Kurdistan Workers Party (PKK), which Turkey, the US and other countries designate as a terrorist group. Their bodies were found at the Kurdish Information Center in the 10th arrondissement of Paris.

Turkish intelligence implicated

Guney denied involvement, though French authorities said they had surveillance footage of him entering the crime scene, as well as DNA evidence on his coat. Sources told French news agency AFP that Guney was a Turkish nationalist who infiltrated the PKK in order to be able to spy on it.

French investigators have also said they suspect MIT, Turkey's national intelligence agency, of being involved in the murders, though Ankara has denied the claims.

Tensions have been growing between Ankara and the PKK, which has been blamed most recently by Turkish authorities for a suicide bombing near a stadium in Istanbul that killed at least 44 people. A splinter group of the PKK later claimed responsibility.

blc/rc (AFP, AP)