Ankara (AFP) - An agent who helped three British schoolgirls cross into Syria to join the Islamic State group was also working as a courier to transfer money to jihadists, a Turkish newspaper reported on Sunday.

Turkey announced Thursday that it had arrested an intelligence agent working as a spy for an unidentified country in the US-led coalition and said he was a Syrian national.

Media reports in Turkey have said he was working for Canadian intelligence -- a claim rejected by Ottawa.

The Milliyet newspaper reported that the man, a dentist using the name "Doctor Mehmed Resid", told Turkish police during questioning that he received the money sent from abroad before it was delivered to IS militants.

The agent said he withdrew the cash from a branch of Western Union and delivered it to Syrian jewellers working in the southeastern Turkish city of Sanliurfa close to the Syrian border, Milliyet reported.

The jewellers then contacted their colleagues in Syria and a middleman would come to their shops.

The agent told investigators that his brother, who lives in the Syrian city of Raqa, an Islamic State stronghold, received the money from the jewellers and delivered it to IS militants, according to Milliyet.

The report did not reveal who sent the money in the first place, only that it came from abroad.

Video footage emerged Friday purportedly showing the same man helping the British girls into a car in Sanliurfa on their way to Syria.

Close friends Kadiza Sultana, 16, and 15-year-olds Shamima Begum and Amira Abase, crossed into Syria after boarding a flight from London to Istanbul on February 17.

They took a bus from Istanbul to Sanliurfa, from where they are believed to have crossed the frontier.