A grieving wife cared for her husband's decomposing body for at least six weeks after he died, police say.
A homicide investigation had been launched, but that was downscaled after it appeared the man died of natural causes in what police described as a mysterious and sad case.
Detective Senior Sergeant Grant Ferguson of the Kapiti Mana Police said it was thought the man died in August and may have been fed and bathed by his wife for as long as six weeks before neighbours noticed a smell and alerted police.
Mr Ferguson said the couple were originally from India.
The woman still denies it was her husband's body; she said it was that of a stranger who arrived in the house the day he disappeared and that really threw police, Mr Ferguson said.
"She still maintains that and that was the real sort of twist or challenge that we had in this."
The bathing of his body may have been a Hindu ritual, but the real reason was still a mystery, Mr Ferguson said.
"I'm not sure if it's mental health issues, but it's a very sad, sad case, no matter what it is.
"She is struggling with the trauma of it and saying things that probably aren't quite right now... (they're) both from India and only the two of them out here...Every possible challenge that could've been thrown up really was... they have no next of kin in New Zealand and things like that."
It was through the tenacity and determination on the part of the lead officer in the investigation that police ultimately got some answers in the case, he said.
"We were able to engage with the Hindu and Indian community in Wellington and they were very helpful... and they've tried to engage with her.
"Initially she was in community health support, but I think she was looking to get out of that and go back to her own life and place."
Police had been affected in dealing with the decomposing body, but there was a very good welfare system in place to support officers, Mr Ferguson said.
The body was so badly decomposed a post-mortem was unable to establish how he died.