BELIZE CITY, Belize (AP) — An autopsy on the body of a U.S. tourist found dead in western Belize has determined that she was strangled to death.

Anne Swaney, 39, died from "asphyxia due to compression of the neck area, throttling and blunt force traumatic injuries to the head and neck," according to the post-mortem report prepared by Dr. Leyden Ken on Friday night.

Swaney worked for ABC-Channel 7 in Chicago. Her body was discovered Friday morning floating face-down in the Mopan River, which flows into Belize from Guatemala.

Police in the border town of Benque Viejo del Carmen were questioning an unidentified Guatemalan national, who was fishing in the area but denied any involvement in her death.

"We currently have him in custody and we will be pursuing an interview for him to give account of himself," Superintendent Daniel Arzu told local TV news.

Swaney was vacationing at the Nabitunich resort in the Cayo district when she was reported missing Thursday.

Police say members of a tour group she should have been part of returned to the resort and couldn't find her.

Her belongings were later found on a deck by the riverside where she had gone to do yoga exercises.

This story has been corrected to reflect that the doctor's first name is Leyden, not Keyden.