Turkey’s official Anadolu news agency said the men were detained and later arrested on suspicion that they are members of the extremist Islamic State group.
Aristidou, 23, from Enfield, north London, had been missing for two years.
“He was arrested after coming from Syria – we think he’s a member of Isis,” a Kilis spokesman said.
Aristidou, who is of Greek heritage, told police he had travelled to Syria to settle rather than fight, according to The Guardian.
He reportedly told investigators he had lived in Raqqa, the de facto capital of IS, and al-Bab, a city formerly under IS control.
Turkish authorities are reportedly seeking to jail him for between seven and 15 years and he could face further prosecution under terror legislation when he returns to the UK.
According to UK Government figures released in November, about 800 people “of national security concern” had travelled to take part in the Syrian conflict.
About half of those had returned at the time the figures were released.
Kleman was traveling with his Syrian wife and four children. His family was put under administrative detention to be deported to the US to keep them together, according to the official.
Anadolu said two Egyptians and four more children were also travelling with the group and will be deported.