A school teacher has been jailed for life without parole for sexually abusing and murdering a 13-month-old boy he adopted with his partner, bringing an end to a case detectives described as one of the most disturbing they had encountered.

Jamie Varley, 37, adopted Preston Davey, at nine months old with his partner, John McGowan-Fazakerley, 32

Police have released a video of Jamie Varley, 37, psychologically torturing Preston, six weeks before he died.

A teacher has been convicted of murdering a 13-month-old boy he adopted with his male partner just months before the child's death.