BEIRUT -- Lebanese authorities have detained a man suspected in the killing of a British woman who worked at the U.K. Embassy in Beirut and whose body was found near the city over the weekend, a police official said Monday.

The woman's murder was a "criminal act" and was not politically motivated, the official said, adding that the suspect had confessed to the killing.

The woman, later identified by British media and friends as Rebecca Dykes, was found on the side of a motorway on Saturday. Sources told CBS News partner network BBC News that it appeared Dykes had been sexually assaulted and strangled to death.

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When she was found, there were no items pointing to her identity and she had no money or a cellular telephone. Authorities released a drawing of her in order for people who know her to come forward and identify her.

Meanwhile, Britain's Foreign Office confirmed the death of an embassy staffer who worked for the Department for International Development.

In a statement released by the Foreign Office, the family requested that the media respect their privacy "at this very difficult time."

"We are devastated by the loss of our beloved Rebecca. We are doing all we can to understand what happened," her family said.

"The whole embassy is deeply shocked and saddened by this news," said British Ambassador to Lebanon Hugo Shorter in a statement, "Our thoughts are with Becky's family, friends and colleagues for their tragic loss."

On Monday, a police official said the suspect was traced through security cameras that showed his car driving from Beirut to the area where Dykes' body was found, just north of the Lebanese capital.

"He was detained at his apartment," the official said. He added that once the plate number of the vehicle was traced through security cameras, the suspect, who is a Lebanese citizen, was identified.

Lebanon's state-run National News Agency said the suspect is a taxi driver who picked up the woman from Beirut's Gemayze neighborhood, known for its restaurants and pubs, then drove to a nearby neighborhood where she lived but did not drop her off there.

Instead, the suspect drove the car to the site where Dykes' body was later found. NNA said the man tried to sexually assault her, then strangled her with a rope. The police have not confirmed those details.

The murder has shaken Lebanon, where such crimes, particularly against foreigners, are relatively uncommon.

Earlier, a forensics official told The Associated Press that the woman was strangled with a rope and that authorities were investigating whether she was also sexually assaulted. Both the police and the forensics official spoke on condition of anonymity because they were not authorized to talk to reporters.

Dykes' friends said she was planning to fly home for Christmas on Saturday.