Turkish police have detained a suspect in connection with the murders of a Syrian opposition activist and her journalist daughter, the private Dogan news agency reported on Saturday.
Aroubeh Barakat and her 22-year-old daughter Halla Barakat were found dead in their Istanbul apartment last week.
The police investigation reportedly concluded they had been stabbed to death, with unconfirmed reports of their throats being cut with the bodies lying undetected for up to three days.
The arrest of Ahmet Barakat, believed to be a relative of the victims, followed analysis of hundreds of hours of security camera footage, according to Dogan.
Police captured him in the northwestern province of Bursa, according to the report, following several raids in the province.
The suspect will be taken to Istanbul for questioning, Dogan reported.
Since the outbreak of the Syrian civil war in 2011, Turkey, according to the government figures, has become home to 3.2 million Syrian refugees, many of them opponents of the regime of President Bashar Assad.
Halla Barakat had been working for a website called Orient News and had previously worked for Turkish state broadcaster TRT.
Syrian opposition activists and journalists have repeatedly complained of threats to their security.
Two Syrian journalists from the city of Raqqa who were opposed to Daesh were found beheaded in southern Turkey in 2015