Grapevine

By PAUL GRAY/

BEHIND MEXICO'S GRIPES. Relations with Mexico have been badly strained by the Drug Enforcement Administration's role in the clandestine snatch of a Mexican physician indicted in the 1985 murder of DEA agent Enrique Camarena Salazar. But some Mexican officials may be worried about more than their nation's sovereignty. Dr. Humberto Alvarez Machain, delivered to El Paso by Mexican bounty hunters in April, could provide testimony on relationships between drug kingpins and Mexico's secret police agency, the Federal Security Directorate (DFS). DEA agents contend that the DFS was the brains behind much of Mexico's drug trade -- and that certain DFS officials helped orchestrate Camarena's death. Camarena and his partners put Alvarez under surveillance after being told that he carried DFS credentials.

With reporting by DAVID ELLIS