By CHERYL BROWNSTLIN
And GLORIA MARINA

A federal grand jury investigating terrorism will begin today to question a Hialeah man about the attempted kidnapping of the Cuban consul in Merida, Mexico, last July.

Gustavo Castillo was returned from Puerto Rico this week on a federal warrant requiring him to appear before the jury as a material witness; he faces no charges. Samuel Sheres, one of his court-appointed attorneys, said Thursday he will seek Castillo's release when his testimony is concluded.

Magistrate Charlene Sorrentino issued the warrant after hearing sworn testimony from an FBI agent regarding possible violations of the U.S. Neutrality Act.

The Jury will ask Castillo what he knows about the July 23 would-be abduction of Cuban Consul Daniel Ferrer Fernandez, which failed after a shootout in which Dartanan Diaz Diaz, a consulate aide, was killed. Two suspects, Gaspar Eugenio Jimenez Escobedo and Orestes Ruiz Hernandez, have already confessed to the attack, Mexican officials say.

A third participant is still being sought.

Mexican police say they found Castillo's passport, Mexican tourist visa and an airline ticket for his trip from Miami to Cozumel, when they arrested Jimenez Escobedo and Ruiz Hernandez in Merida.

"The Mexican officials also found additional evidence, including two guns which were used during the shooting," states a sworn FBI statement presented to Magistrate Sorrentino.

"My investigation shows that one of the firearms was purchased in Miami, Florida, in May of 1976 and was given to one Gustavo Castillo in June of 1976," the statement continues.

The grand jury has already heard testimony from dozens of persons about terrorism in Miami and other U.S. cities since it was empanelled last October.