One of the men involved in the Paris attacks visited the UK earlier this year, The Guardian reported.
The un-named man met people in London and Birmingham and was “suspected of having the intention and capability of plotting or assisting terrorist activity against the UK”. However, the Home Office has not confirmed the report.
This comes after the Wall Street Journal said the man behind the plot, Abdelhamid Abaaoud, is thought to have links with Birmingham.
In a statement, West Midlands police, which covers the Birmingham area, said officers are “working hand-in-hand” with counter-terrorism colleagues in London and security services.
Assistant Chief Constable Marcus Beale said: “The West Midlands Counter Terrorism Unit is working … to provide support to the French and Belgian investigations and of course to address any associated terrorism threat to the UK.”
Abaaoud was known to have trained as a fighter with the so-called Islamic State and had “criss-crossed between Syria and Europe and back again”.
He was killed in a police raid in the Paris suburb of Saint-Denis five days after the attacks.
Officers from Scotland Yard’s counter-terrorism command had been working in Paris since last month’s attacks to help with investigations and they are now following up leads within the UK, according to reports.
The UK terrorism threat level is currently set at severe – meaning the prospect of an attack is “highly likely”. Security plans for the UK are currently under review.
The government stated that at least seven potential plots had been foiled in the last year, but not on the same scale as the one carried out in Paris.
11 Isis fighters took part in the attacks on 13 November, which left 130 people dead and more than 350 wounded.