The 55-year-old man, who now lives in Thailand, was arrested on Sunday while visiting Brisbane.
The woman, 54, drowned while kayaking with the man at Lake Samsonvale north of Brisbane in November 2020. The pair were known to each other.
The woman could not be revived when they returned to shore despite onlookers and emergency services performing CPR and she died at the scene.
"Initially, the woman's death appeared to be non-suspicious," Queensland Police said in a statement.
However, a coronial inquiry led to detectives declaring it suspicious and launching Operation Victor Harlow.
The "complex and lengthy" probe gathered witness and expert statements, including information about the conditions of the lake at the time of the woman's death.
"Police will allege the man was involved in the drowning death of the woman," police said.
The man has been charged with murder, fraud and attempted fraud.
He was refused police bail and to appear in Brisbane Magistrates Court on Monday.
"Incidents are not always what they initially seem, so I thank the detectives for their diligent work in this lengthy and arduous investigation," Detective Acting Inspector Steve Windsor said.
"This is also an important reminder to the community to report any suspicious circumstances to police as you see them.Â
"Even if they seem insignificant, they may be an important piece to the puzzle in an investigation."
23°C