MEXICO CITY — The daughter-in-law of a politically influential British magnate was in custody in Belize on Saturday, under investigation in the shooting death of a police superintendent.

Police Commissioner Chester C. Williams told 7 News Belize television that Jasmine Hartin initially balked at making a statement, preferring to wait for the presence of her attorney. She was found on a dock near the spot where police Superintendent Henry Jemmoth was found dead early Friday.

“In the absence of an explanation then she would have to be treated as the killer and we will proceed accordingly,” Williams said.

Hartin is the partner of Andrew Ashcroft, son of Michael Ashcroft, a former deputy chairman of Britain’s Conservative Party and a major financial backer. He also holds Belizean citizenship and was once its representative before the United Nations.

The incident “seems rather personal and not an attack,” Williams said. “From what we know is that they are friends. From what we have been made to understand they were drinking. From investigation they were alone on the pier and yes they were both fully clothed.”

He said Hartin “was somewhat in a emotional state walking herself on the pier. We believe that she is to some extent affected by it.”

LinkedIn accounts indicate that both the younger Ashcroft and Hartin were connected with a local resort in Belize.