Texas carried out the execution of a Mexican-born rapist and killer late Tuesday evening, defying orders from US President George W Bush and a ruling by an international court, local news reports said.

Jose Ernesto Medellin Rojas was executed Tuesday for the rape and murder of two Houston teenagers 15 years ago, after the US Supreme Court rejected his request for a reprieve in a split vote, the Houston chronicle newspaper reported.

Rojas was one of six gang members convicted for the 1993 hour-long rape and brutal murder of two Houston girls, ages 14 and 16, as part of a gang initiation ceremony.

The case has become a cause celebre among death penalty opponents.

Since 1997, Medellin's lawyers and Mexico have been challenging Medellin's death penalty conviction because he is a Mexican citizen and Mexican officials had not been informed of his need for legal help during the trial.

Under the Vienna Convention of Consular Relations, arrested suspects from foreign countries are supposed to have access to their own consulates to seek legal assistance.

In 2004, the International Criminal Court of Justice agreed with Mexico. Bush, a former governor of Texas took the unusual step in 2005 and ordered Texas to reopen the case.

Texas insisted it would only bow to the US Supreme Court, and the state's Governor Rick Perry indicated he had no intention of staying the execution.

Groups opposed to the death penalty warned that Medellin's execution in violation of an international court order "will place Americans abroad at risk."

"If the US disregards its legal obligations in this case, it will be hard pressed to argue that other countries should respect the rights of US citizens under arrest," David Fathi of Human Rights Watch in Washington said.