According to Facebook:

The body of an elderly Canadian man was found sitting against a bathtub around 11AM on January 18 2016. The victim was found in room D1 of Marina Hotel, located in Group 27, Phum 3, Sangkat 3, Sihanoukville.
The victim was identified as RUSSELL GERALD WALTER, male, Canadian national, born on 18/01/1947, 69 years old, passport number GBXXXXXX valid until 30/12/2015.
The cause of death is still unknown.
Currently the body is stil at the scene awaiting the police and a doctor to do an examination.

Afterwards the identity of the victim was changed to US national Mahoney Shane Thomas.

Read more here.