Police have named a mother and daughter who died in a Bank Holiday boating tragedy on Lake Windermere.
Kelly Webster, 36, and 10-year-old Lauren Thornton are believed to have suffered fatal gas poisoning. Both are from Leyland in Lancashire.
Ms Webster's partner, Matthew Eteson, 39, who was also on board, was treated in hospital before being released today.
A Cumbria police spokesman said officers were alerted to reports that three people on a privately-owned boat were having serious breathing difficulties.
“On arrival, Mrs Webster and her daughter, Lauren, were being treated by paramedics and were airlifted to Royal Lancaster Infirmary, where they tragically died. A man, 39, from Leyland, who was also on the boat, remains in Royal Lancaster Infirmary receiving treatment," the spokesman said.
"Police are not treating the deaths as suspicious, and it is suspected that the deaths were caused by some form of gas poisoning. Inquiries continue to be conducted by officers on behalf of the coroner," he added.
Tony Rothwell, who runs the Bowness Bay marina, told the Daily Telegraph that he was told by lake wardens that the boat had been fitted with a faulty generator.
The generator was connected to a fan heater, which is thought to have been turned on. Temperatures around the Lake District remained only just above freezing throughout the day.
Mr Rothwell said: "It was an amateur job. The boat had been fitted with a generator and the exhaust has leaked. It had been a very cold day and the fan heater was connected to the generator. It is a terrible tragedy."
Emergency services were called to the private boat at around 4pm on Monday. The incident, at a jetty near Bowness, was witnessed by Dragons’ Den star Duncan Bannatyne, who was nearby. He posted a photograph of the scene on Twitter, saying: “Tragic accident over there I am afraid.”
Police said Mr Eteson, who is the owner of the boat, raised the alarm after experiencing breathing difficulties.
Detective Inspector Mike Brown, who is leading the investigation, said Ms Webster and her daughter were both found in the rear of the boat.
He said he believed the deaths of Ms Webster and her daughter "may be as a result of carbon monoxide inhalation".
He said: "What we are looking at specifically is an aftermarket generator that has been fitted in the engine compartment of the boat which we believe may be the cause of this.
"But, again, it's still early stages in the investigation so we can't rule anything out."
Although it is not known what gas caused the deaths, the tragedy prompted renewed warnings over the dangers of carbon monoxide poisoning.
The so-called silent killer causes 50 fatalities a year in the UK leaving a further 200 seriously ill. Odourless and tasteless, symptoms from the gas include headache, dizziness, vomiting and shortness of breath.
Carbon monoxide is produced when fuels such as wood, gas or coal do not burn fully. It can be caused by poorly installed heating appliances or blocked chimneys or flues.
Last Easter a six-year-old girl died during a family camping trip to the New Forest as a result of fumes given off from a barbecue.
Windermere is England’s largest natural lake and a popular destination for watersports.