Abdel-Majed Abdel Bary, a former rapper from west London who once posted an image of himself holding a severed head on Twitter, has been arrested in the southern coastal city of Almeria, the source said.
Police had on Tuesday announced the arrest of "one of the most wanted foreign terrorist fighters of Daesh" -- the Arabic acronym for Islamic State -- identifying him as an Egyptian national but without giving his name or saying exactly when he was detained.
Speaking to AFP, a Spanish judicial source confirmed it was Bary.
Police said the suspect "had recently entered Spain illegally and was found hiding in a rented flat" in Almeria where several other people were also arrested.
"He is one of the most wanted terrorists in Europe on grounds of his criminal record within the ranks of Daesh and because he is extremely dangerous,"
Before arriving in Spain, Bary spent "several years in conflict zones in Syria and Iraq", police said, describing him as presenting "some very strange personality traits and an extremely violent criminal profile which had brought him to the attention of Europe's police and intelligence services".
Born in London, Bary shot to notoriety after his Twitter post in which could be seen holding up the severed head alongside the caption: "Chillin' with my homie, or what's left of him".
He is the son of Adel Abdel Bary, an Egyptian who in 2015 was sentenced to 25 years behind bars by a US court for his involvement in the 1998 bombings of the US embassies in Kenya and Tanzania, which killed 224 and wounded more than 5,000 others.
