Edgar Tayamo was put to death by lethal injection on Wednesday evening at Huntsville prison. The 46-year-old had been convicted of killing a Houston police officer in 1994. He declined to make a final statement and was pronounced dead at 9:32 p.m. (0332 UTC).

Tayamo's lawyers, who say he spoke very little English at the time of his arrest and was mentally handicapped, sought a last-minute reprieve from the Supreme Court but their appeal for a stay of execution was denied within hours.

Mexico objects

The Mexican government and Tayamo's attorneys denounced his execution and condemned it as a violation of international law, saying he was protected under a provision of the 1963 Vienna Convention on Consular Relations.

"The Mexican government urges effective action and calls for avoiding other sentences issued in contempt of the International Court of Justice's ruling in order not to damage the regime of consular assistance and protection agreed between the countries," the Foreign Ministry said in a statement.

US Secretary of State John Kerry had previously asked Texas to delay Tayamo's execution, saying it "could impact the way American citizens are treated in other country," a position reiterated by the State Department on Wednesday.

Denied consular rights

In 2004 the International Criminal Court of Justice in The Hague, Netherlands ruled that Tayamo was among four dozen Mexican nationals on death row in the US who had not been properly advised of their consular rights.

"If he had had the assistance of the Mexican consulate at the time of trial, Mr. Tayamo would never have been sentenced to death," defense attorneys Sandra Babcock and Maurei Levin said in a statement.

"The execution of Mr. Tayamo violates the United States' treaty commitments, threatens the nation's foreign policy interests, and undermines the safety of all Americans abroad," they added. "It is now imperative that Congress promptly act to ensure passage of legislation that will bring the US into compliance with its international legal commitments and provide judicial review to the Mexican nationals who remain on death row in violation of their consular rights."

Tayamo is the third Mexican national not afforded proper judicial review to be executed in Texas. A fourth is scheduled to be put to death in April. Texas executes more inmates than any state in the US.

dr/hc (AFP, AP, Reuters)