Image caption This is only the sixth time that the border gate has been opened

A US man who wed his Mexican fiancée at the border with Mexico last month turned out to be a convicted heroin smuggler, local media report.

Background checks failed to reveal Brian Houston was awaiting sentencing in San Diego at the time, and the US Border Patrol approved the event.

The wedding was part of a "Door of Hope" event which allows meetings between people not allowed to cross.

The BBC and other media reported on the unusual wedding.

Joshua Wilson, from an organisation representing border guards in San Diego, told the San Diego Union-Tribune that agents were "upset".

"They feel like they were taken advantage of, feel like they were duped," he said. "Turns out we provided armed security for a cartel wedding."

The incident may put the annual event on jeopardy.

Houston, who is from San Diego, signed official Mexican documents with Evelia Reyes of Mexico, making them husband and wife.

"It's a statement that love has no borders," Houston said afterwards.

He had been arrested in February at another border crossing after police found 19.5kg (43lb) of heroin, 21kg of methamphetamine and 19.5kg of cocaine in his car, according to the complaint.

Image caption America's new generation of addicts

However, he was released on bail with a ban on leaving the US after he pleaded guilty in court in May. His sentencing is in February.

A Border Patrol spokesman, Takae Michael, said Houston had been screened through an internal vetting process based on information provided by the event's organisers, the Border Angels group, and no criminal activity had shown up.

Nor were his plans for the wedding reported to the Border Guard in advance.

"They showed up dressed for a wedding," Mr Wilson said. "The agents there were powerless to stop it. We were certainly put on the spot."

The annual meetings on the border between San Diego and Tijuana started in 2013.

Enrique Morones, executive director of Border Angels, said his organisation had never done "any background checks as the Border Patrol advised us they will do all background checks and advise us which families have been cleared".