Deaths of Lancaster man and his family on a hiking trail in California not being treated as murder
The bodies of Jonathan Gerrish, 45, his wife Ellen Chung and their daughter Muji - along with their dog Oski - were found by search teams last Tuesday in an area of the Sierra National Forest known as Devil's Gulch.
Officials had been looking into whether poisonous algae killed the family but lifted the hazmat declaration on Wednesday.
The bodies of the family were airlifted out of the area that afternoon.
The Marisopa County Sheriff's Office is now ruling out homicide in the hiking trail deaths, Fox News reports.
Spokeswoman Kristie Mitchell said: 'Initially, yes, when we come across a family with no apparent cause of death, there's no smoking gun, there's no suicide note, there's nothing like that, we have to consider all options.
'Now that we're five days in, no, we're no longer considering homicide as a cause of death.'
Mr Gerrish, originally from Lancashire, had been a software developer for Snapchat and previously worked for Google.
Police had earlier announced that they were treating the mysterious deaths of the British software developer, his wife, their one-year-old toddler and the family dog as a homicide.
County Sheriff Jeremy Briese said: 'I've been here for 20 years, and I've never seen a death-related case like this.
'You have two healthy adults, you have a healthy child and what appears to be a healthy canine all within a general same area,' the sheriff explained.
'So right now, we're treating the coroner investigation as a homicide until we can establish the cause.'
Officials first began looking into the toxic algal bloom from the Merced river as the cause for what overcame the family, along with possible escaping gas from abandoned gold mines.
But Briese said they could not find any disused shafts in the vicinity.
'We have not found any old mine shafts near the area,' he added. 'There are some mine shafts, but we can't confirm if that's the cause yet.
Police are still waiting on the results of post-mortem examinations.
Further toxicology reports could take up to six weeks.
Autopsies and toxicology tests are planned for Thursday in Stanislaus County.
California State Water Resources Control Board and Mariposa County are now re-testing the river water for cyanobacterial toxins, which can form in algal blooms.
Searchers began looking for the family after they were overdue on a day hike and reported missing last Monday.
They were found on the Savage-Lundy hiking trail near Hites Cove, which was once a thriving mining community after gold was discovered in 1861.
Gerrish was a software developer for Snapchat, had previously worked for Google.
He is originally from Lancashire, England and graduated from Newcastle University.
Speaking from his home in Bamber Bridge, Lancashire, his father Peter, 70, said: 'The family are just in shock - heartbroken.'
When asked whether he had received any further updates or was in contact with US authorities, the grandfather added: 'We haven't heard anything more.'
Kristie Mitchell, a spokeswoman for the sheriff's office has said investigators are still working to determine the cause of their deaths and 'looking at all possibilities.'
'It could be a carbon monoxide situation,' which is why the department had been treating the scene as a hazmat situation she explained.
'There are several abandoned mines up in the area and in an abundance of caution or recovery team is taking precautions for any poisonous gases, particles in the area,' Mitchell added. 'So far, there has been no measurable poisons registered.'
Mitchell also did not rule out possible exposure to toxic algae. She noted that the bodies of the deceased showed no signs of trauma, and no suicide note was found.
'It is a very bizarre situation,' she said.