One of three attackers shot dead during an attack near London Bridge on Saturday evening had an Irish identification card, the Irish state broadcaster RTE reported, citing Irish police sources.
The Irish police declined to comment on the report.
"The British police discovered the Irish identity card on the body of one of the three London attackers after he was shot dead," RTE security correspondent Paul Reynolds said in a report.
"Gardai (Irish police) were contacted and have established that he lived in Dublin for some time. The man is believed to have been of Moroccan origin and is married to a Scottish woman," he said.
The man had not come to the attention of the Gardai in relation to any crime or security issues, the report said.
The head of the Irish police force was due to hold a special meeting of security and intelligence officers in Dublin on Monday morning in relation to the attack, RTE reported.
At least seven people were killed when the three men rammed a van into pedestrians on London Bridge and then stabbed revellers in nearby bars, British police said.
An Irish police spokesman said the force was providing assistance to colleagues in the British police and would answer any enquiries from them in relation to the identity of any individuals.