Riley Holt, 8, Keegan Unitt, 6, Tilly Rose Unitt, 4, and Olly Unitt 4, all died in the fire in Stafford last February, and an inquest was told their parents had been smoking in bed despite a warning from social services

A fire which killed four young children was caused by fumes from a discarded cigarette, an inquest into their deaths heard.

Siblings Riley Holt, 8, Keegan Unitt, 6, Tilly Rose Unitt, 4, and Olly Unitt, 3, were all killed in the horrific blaze in Stafford, on February 5 last year, Stoke on Trent Live reports.

Their mum and dad Natalie Unitt and Christopher Moulton were initially arrested on suspicion of manslaughter by gross negligence.

But police later confirmed no further action was being taken against them after a file was passed to the Crown Prosecution Service.

The blaze was likely to have started in the main bedroom, an investigation by Staffordshire Fire and Rescue Service found.

The couple disputed the experts’ conclusions at the coroner’s court hearing on Thursday.