One of the London Bridge terror attackers was carrying an ID card issued in Ireland when he was shot dead, security sources in the Republic have confirmed.
Police chiefs in Dublin said they were liaising with counterparts in the UK amid reports that the killer had Irish papers.
"An Garda Siochana is providing every assistance to our colleagues in the London Metropolitan Police in relation to the terror attack in London," a spokesman said.
"We will process all requests from the UK authorities in relation to inquiries into individuals, identities or any other matter."
There are unconfirmed reports that the man who had been carrying the Irish-issued ID may have claimed to be from Morocco and that he was married to a woman from Scotland and had lived in Dublin.
Gardai are investigating whether the ID card belonged to the dead man and if the documents are legitimate.
It is understood inquiries are continuing into whether the man was given an Irish ID card issued by the Garda National Immigration Bureau.
The plastic credit card-sized documentation is given to people from outside the EU. It has a person's certificate of registration which states they have permission to stay in Ireland. It must be carried at all times.
There are also inquiries into whether the man had been given paperwork after landing in Ireland to claim asylum or if he had an ID card issued under EU treaties which allowed him to live in Ireland with his family.
Garda Commissioner Noirin O'Sullivan was holding a meeting with the force's anti-terror and intelligence chiefs as they co-operate with the Met investigation.
Ireland's security and defence chiefs have kept terror threat levels in the country under constant review since the Manchester and London attacks.
The Department of Justice said the risk of an incident is "possible but unlikely".