TUNIS/MILAN (Reuters) - The Moroccan arrested in Italy on suspicion of involvement in the Islamist militant attack on Tunisia's Bardo Museum provided the weapons, a Tunisian official told Reuters on Thursday.
Italian police said on Wednesday they had arrested Abdelmajid Touil, aged 22, in connection with the March 18 attack in Tunis in which 21 tourists were shot dead.
"(He) is a weapons smuggler ... he brought weapons for the Bardo Museum attackers from Libya to Tunisia before the date of the attack," said the official, who asked not to be named.
Touil reached Italy on a migrant boat in February, police in Milan said, fuelling fears that Islamic militants could be among migrants crossing the Mediterranean by boat to Europe.
They said when announcing his arrest that Tunisian authorities believed he had been involved in both planning and carrying out the March attack.
However a source close to the Italian investigation told Reuters on Thursday investigators were "99 percent sure" Touil was in Italy during the attack.
The source said Tunisian authorities had not yet supplied Italy with details about what Touil was suspected of doing or when, despite having issued an arrest warrant.
The detained man's mother, Fatima Touil, who lives in the apartment outside Milan where he was staying at the time of his arrest, also said he was in Italy when the killings took place.
"He doesn't have any ties with any terrorists," she was quoted as saying in an interview by the Corriere della Sera newspaper.
The judicial source said suspicion had been raised about Touil's movements because he had arrived in Italy on a migrant boat, despite his mother's resident status in Italy which would have allowed him to enter the country officially.
Interior Minister Angelino Alfano told parliament on Thursday that Italy was uncertain about his movements after being rescued from the boat.
Tunisia has said it has arrested the great majority of those responsible for the attack, which it says was a cell of 23 militants with overlapping allegiances to a number of hardline Islamist groups.
Reporting by Tarek Amara in Tunis, Emilio Parodi in Milan and Steve Scherer in Rome; editing by Andrew Roche