Mexico's attorney general escalates fight with U.S. over former minister

MEXICO CITY (Reuters) - Mexican Attorney General Alejandro Gertz said on Tuesday he was considering elevating to international courts a dispute with the United States over Mexico dropping an investigation into a former defense minister.

Gertz said the U.S. Department of Justice had effectively declared ex-defense minister Salvador Cienfuegos innocent when it sent him back to Mexico and dropped U.S. charges against him after he was arrested in California last year.

He defended his own decision to close a Mexican probe into whether Cienfuegos had colluded with a drug cartel, saying the U.S. evidence was inconsistent, included questionable physical descriptions of the retired general, and used testimony from two dead witnesses.

The spat, one of several serious hiccups during the Trump administration, risks souring Mexico's most important bilateral relationship as the two countries seek to turn over a new leaf with the inauguration of President-elect Joe Biden this week.

In an interview on Mexican radio, Gertz said he was being accused of bias in favor of Cienfuegos, something he described as "a lynching," and that he was exploring his legal options at the level of "all" courts to which he had access.

He did not specify to which international tribunal he could go, but said he would consult with a Mexican judge who served at the International Court of Justice at The Hague.

The Justice Department last week said it was "deeply disappointed" that Mexico had decided to close the investigation, saying it fully stood by its own evidence and charges in the matter.

It also said Mexico's decision to publish the evidence from the investigation violated a treaty of mutual legal assistance, and called into question future information sharing.

U.S. prosecutors dropped their case and returned Cienfuegos to Mexico in November citing diplomatic sensibilities, after his dramatic arrest in Los Angeles a few weeks earlier on charges of helping a cartel move tonnes of cocaine and other drugs.

(Reporting by Lizbeth Diaz and Raul Cortes; Writing by Frank Jack Daniel; Editing by Alistair Bell)