A suspected Islamic State terrorist captured by Kurdish-led forces in Syria a week ago lived in Ireland for about a decade and was on a Garda watchlist here.

Alexandr Ruzmatovich Bekmirzaev (45), who is originally from Belarus, came to Ireland in the early 2000s and obtained Irish citizenship and an Irish passport. He worked in retail and as a security guard in Dublin during his time here, sources said.

During his time in the State, gardaí received information from a foreign intelligence agency that he was an active supporter of radical Islamist groups. He was put on a watchlist and monitored by members of the Special Detective Unit.

In 2013 he left for the Middle East, where it is understood he joined a group linked to Islamic State, also known as Isis. He made his way to Syria, where he fought in the civil war there which has to date claimed almost 400,000 lives.

The Department of Justice has previously estimated that about 50 Irish citizens have travelled to Syria to fight in its civil war, many of them for extremist groups like Isis. At least three have been killed in the fighting.

The Syrian Democratic Forces (SDF), which is battling the remnants of Isis in Syria, announced yesterday that it had arrested the man in the city of Deir al-Zor along with two US and two Pakistani fighters.

In a statement, the SDF, a US-supported militia, said Isis terrorists had attempted several attacks on its forces recently.

“In this context, a group of terrorists who had been preparing to attack the civilians who were trying to get out of the war zone in masses was detected.”

Asked about the matter, a Garda spokesman said: “The individual may be identical to a naturalised Irish citizen who, it is understood, departed Ireland in 2013. An Garda Síochána is monitoring the reported development.”

Taoiseach Leo Varadkar said he had been informed that “an Irish passport holder, an Irish citizen” had been taken into custody in Syria.

“We don’t know the details of that so I can’t comment on it in any detail, but what I can say is that any Irish citizen around the world is entitled to consular assistance and will get that,” he told reporters during a visit to Mali.

A Department of Foreign Affairs spokesman said it was looking into the matter but had not received any requests for consular assistance.

‘Wake up call’

Security and anti-terrorism expert Declan Power said it was a matter of concern that the man captured in Syria had obtained Irish citizenship despite coming to the attention of the Garda’s crime and security branch.

“We can’t be complacent about the reach of extremism into this State from other locations. It’s a wake up call for us not to be complacent,” said Mr Power, a former member of the Defence Forces.

“It behoves us to look a bit more closely at how somebody was able to obtain citizenship if they were under suspicion of activities that would be damaging to this State and our partner states.

“We shouldn’t be entirely surprised that an Irish citizen has been found. It’s not that long ago since the death of Terence Kelly who was born and raised in Ireland who had gone off to throw in his lot with Islamic State.

“What should be a matter for concern is that this individual is alleged to have come to Ireland from another State, settled here with his family and worked and obtained Irish citizenship,” Mr Power told RTÉ’s Morning Ireland.

“Somewhere along the line he came to the attention of the Garda Síochána’s crime and security branch apparently based on reports from external partner agencies.

“Maybe what we need to look at more closely is the level of scrutiny we can apply to somebody when they come to the State. If this individual managed to obtain citizenship and yet seemed to have been engaged in activities outside of the State before he came here, it raises questions that are worth asking because this kind of thing is not going to die off just because Islamic State, one iteration of extremism, is dying out, but extremism isn’t dead and gone with the death of Islamic State.”

Kelly (49), a former nurse from the Liberties in Dublin, who was also known as “Taliban Terry” or “Khalid Kelly”, died after carrying out an Islamic State suicide bombing in Iraq in November 2016, according to the jihadist group.