MEXICO CITY (AP) _ A judge set free a man accused of killing an American businessman, saying the suspect was a ``modern Robin Hood,'' local media reported Monday.

The U.S. Embassy said it was disturbed by the comment reportedly made Sunday by the judge who released Alonso Gonzalez Sanchez. The suspect was accused of fatally shooting Mexico City-based real estate executive Peter Zarate during a robbery last month.

In ordering the man's release, Judge Maria Claudia Campuzano was quoted by local media as saying, ``(Gonzalez) is a modern Robin Hood, who not only shares what he earns from robberies, but gives his companions more money and doesn't earn anything himself.''

Campuzano would neither confirm nor deny the media reports in a telephone interview Monday night with The Associated Press. ``I can't speak over the phone. These phones are tapped,'' she said, speaking from her courthouse office.

Gonzalez was one of five men arrested Dec. 30 on charges he had targeted foreign tourists and residents for robberies after they boarded taxis.

The embassy said in a news release that it was formally seeking an official explanation of the judge's decision.

``We are deeply disturbed by published accounts attributing strange remarks to the judge who ordered the release,'' the statement said.

The embassy also noted that the judge ``is alleged to have claimed, among other things, improper behavior on the part of Mr. Zarate's widow and the existence of some motive for the crime other than robbery.''

``We cannot imagine what basis the judge has for any of these remarks,'' the statement said.

Police said all five men confessed to robbing Zarate on Dec. 15. Investigators said Gonzalez Sanchez shot Zarate in the chest when the executive resisted his attackers.

Zarate, 40, was deputy director of sales in Mexico for the New York-based real estate company Cushman and Wakefield Inc. He had been living in Mexico City for about three years. He was married and the father of four children.

Before coming to Mexico, Zarate lived in Newport Beach, California, where he joined the Cushman and Wakefield in 1991.

His shooting death prompted the embassy to stiffen a warning against using street taxis in the crime-plagued Mexican capital.

The embassy had issued a similar alert in June, warning Americans not to hail taxis on the street because of a rash of robberies and assaults by criminals posing as taxi drivers.