A ministry statement said Spanish citizen Yassin Ahmed Laarbi was arrested Monday in the Spanish north African enclave of Ceuta.
Police detained eight suspected members of the network June 21 in Ceuta. Laarbi could not be found during that operation.
The group is said to have sent 50 militants to Syria. The statement said Laarbi was also looking to go to Syria.
The group allegedly trained and financed the militants at bases in Ceuta and in neighboring Morocco.
In June, the ministry said the recruits fought against the regime of Syrian President Bashar Assad and some had taken part in suicide bombings.