Police believe the blaze was started deliberately

A fourth body, believed to be that of a young child, has been found by police investigating a fatal fire in the North earlier this week. 

The body of a woman and two children were discovered at a house in Derrylin on Tuesday. 

A 27-year-man is being questioned 'on suspicion of murder' following the blaze.

In a statement this afternoon, PSNI Detective Inspector Peter McKenna said: “Post mortem examinations will take place in order to positively identify the victims involved in this appalling incident. 

“I believe the fire was started deliberately and we are working hard to progress the investigation into this very complex crime scene."

He added that the fire was 'ferocious' and caused significant damage to the house.