ISTANBUL (Reuters) - Turkish police arrested a suspect on Saturday in the killing of a Syrian opposition activist and her journalist daughter in Istanbul, a police source said.

Ahmet Barakat, a distant relative of the two women, was arrested in the city of Bursa, 90 km (55 miles) south of Istanbul, the source said, adding the motive for the killings was not known.

The bodies of 60-year-old Orouba Barakat and her 22-year-old daughter Halla were found just over a week ago in their apartment in Istanbul’s Uskudar neighborhood in the Asian side of Istanbul.

Turkish media said Orouba Barakat was investigating reports of torture in prisons run by the Syrian government. It said she had initially lived in Britain, then the United Arab Emirates before coming to Istanbul.

Hurriyet newspaper said Ahmet Barakat was arrested after a three-day operation. He was identified by CCTV footage and police were searching his house, the paper said.