A man was found guilty of murder after he caused the death of his stepson after the toddler interrupted him watching porn.

2-year-old Keigan O’Brien died after suffering a head injury while in the care of Martin Currie.

The court also found that the boy had suffered from a broken spine, broken ribs and a broken arm.

Currie, 36, was sentenced for life, with a minimum term of 22 years as he was found guilty of the “violent murder of a blameless two-year-old”.

“These offences involved the grossest abuse of a position of trust,” said Justice Eady.

“You placed yourself in the role of Keigan’s father, your duty was to protect him, instead you abused, injured and killed him.”

Keigan’s mother, Sarah O’Brien, 33, was found guilty of causing or allowing the death of a child and sentenced to eight years in prison.

“The jury found that you were aware, or ought to have been aware, of the risk of serious physical harm posed to Keigan by Martin Currie,” Eady said.

“At the very least, you failed to protect Keigan, leaving him with Martin Currie to be subjected to the very significant force used in the incident that led to his death.”

Keigan suffered from brain bleed, which is believed to be caused by having his head hit against a wall or floor.

The court also found that Currie searched the internet for terms including “irregular breathing”, “gurgling” and “unconscious” two hours before calling for help.

“Tragically, little Keigan O’Brien’s life came to an end only four days after his second birthday ,” CPS’ Jill Brookes said.

“He was killed in his own home – the place where he should have been safest from harm.”

“Having heard all the evidence, the jury decided that Currie inflicted fatal injuries on the defenceless little boy, and O’Brien took no steps to protect her child,” Brookes added.

“They both then lied about what had happened. The pair are now facing lengthy prison sentences.”