The man believed to be the coordinator of the Nov. 13 terrorist attacks in Paris had previously traveled undetected to Britain despite being named in an international arrest warrant for his role in a foiled plot in Belgium in early 2015, European law enforcement officials said Monday.
Officials said they had recovered photos from the cellphone of the man, Abdelhamid Abaaoud, that included snapshots of major London landmarks. The confirmation that Mr. Abaaoud had been able to enter Britain, reportedly through a ferry terminal at Dover, led the opposition Labour Party on Monday to call for an “urgent review” of security at British seaports.
Belgian law enforcement officials confirmed that photographs of British landmarks were on Mr. Abaaoud’s cellphone, which was captured by the French police during a raid in the Paris suburb of St.-Denis five days after the attacks. Mr. Abaaoud and two others were killed in the raid.
The exact dates of Mr. Abaaoud’s trip and the full list of places he visited remain unclear, as do his reasons for visiting Britain.
Mr. Abaaoud is the second person connected to the Paris attacks who is believed to have visited Britain in the months leading up to the attacks. According to French news media reports, Mohamed Abrini, who disappeared after being seen traveling between Paris and Brussels with one of the central figures in the attacks, Salah Abdeslam, was seen near Birmingham, in England’s Midlands region, in July.
Investigators have not said how they think Mr. Abaaoud entered Britain, but it is possible that he did so using either a false identity card or one borrowed or stolen from another person.
Eric Van der Sijpt, a spokesman for Belgium’s federal prosecutor, said the suspects in the Paris attacks “are known to travel through Europe using false identity cards,” adding, “Our investigation has shown that they have done so repeatedly.”
During 2015, Mr. Abaaoud’s ties to the Islamic State became increasingly clear. After a foiled attack in Verviers, Belgium, the Belgian authorities put out an international arrest warrant for him. In the February issue of the Islamic State’s magazine, Dabiq, Mr. Abaaoud boasted that he was able to travel freely to and from Europe. In July, a Belgian judge sentenced him to 20 years in prison in absentia for being part of a recruitment network in Europe for the Islamic State, also known as ISIS or ISIL. The report of Mr. Abaaoud’s visit to Britain appeared in The Guardian.
The claims increase pressure on the British government to take additional security steps, especially at its ports. The home secretary, Theresa May, was criticized last week after it emerged that the man many believe to have been featured in the latest Islamic State video, Siddhartha Dhar — also known as Abu Rumaysah — left Britain, also via the port of Dover, while on police bail.
On Monday, Andy Burnham, who speaks for the Labour Party on police and security issues, said the latest reports added to “the growing questions about border security at our seaports.”
“Not only did we discover last week that a U.K. terror suspect on bail waltzed out at the border, we now learn a terror suspect from the Continent freely walked in through the same route,” he said in a statement.
Mr. Burnham described the ferry border as a “weak link” and urged the home secretary to “conduct an urgent review of border security at ferry terminals and provide urgent reassurance that passports are being properly checked on exit and arrival in the U.K.”
The Metropolitan Police and the West Midlands Police, which cover the two areas that Mr. Abaaoud is reported to have visited in Britain, said they could not confirm that he had been in the country.
The Home Office declined to comment on Mr. Burnham’s statement, or on the reports that Mr. Abaaoud had traveled to Britain.