The Moroccan authorities have confirmed that they are holding a man suspected of involvement in the 11 March train bombings in Madrid.
Hicham Ahmidan was arrested on drugs-related charges
Hicham Ahmidan, 24, was picked up by police in Tangiers on 25 March, Moroccan security officials said.
They said he was held on drugs charges, but made no mention of other offences.
Mr Ahmidan - a relative of one of the Madrid suspects who died during a police raid in April - is wanted by Spain in connection with the bombings.
He is among five men named in international arrest warrants issued on 26 April.
Morocco's national security agency said Mr Ahmidan illegally emigrated to Spain and later turned to drug dealing in Madrid.
They said he returned to Morocco to visit his family in early March, and was arrested later that month.
Mr Ahmidan is related to Jamal Ahmidan, alias El Chino or Mowgli, one of the suspected leaders of the Madrid attacks.
The Madrid attacks killed 191 and injured hundreds
Jamal Ahmidan is one of seven men who appeared to have blown themselves up deliberately when their flat was surrounded by Spanish police on 3 April.
The bombing of commuter trains in Madrid killed 191 people. The attacks are believed to have been the work of Islamic militants with links to al-Qaeda.
The Spanish authorities have brought provisional charges against more than a dozen suspects - many of whom are Moroccans.