Abrini was seen visiting Manchester in 2015.
After having been spotted on CCTV cameras at Brussels Airport shortly before the blasts, he became known as "the man with the hat", the third terrorist that got away. Police started a large-scale search. Abrini was finally arrested in Brussels and remains in custody.
Investigators already knew that Abrini stayed in Manchester, but they now try to find out whether he had contacts with the Manchester bomber. Abrini is a 32-year-old Brussels-born Belgian of Moroccan descent. He was also seen receiving £3000 in cash handed over in a park in Birmingham, ahead of the Paris and Brussels terrorist attacks, in July 2015.