The community in Omagh was rocked yesterday by the police announcement that they were launching a murder inquiry following the blaze which claimed the lives of Arthur McElhill, Lorraine McGovern, and their five children, James (10 months), Caroline (13), Bellina (4) and Clodagh (18 months).

And following the revelation that Mr McElhill was considered to be the chief suspect in the case, it has also emerged that tests have found petrol was involved in the blaze.

The shocking new twist came as a key witness revealed how he was the last man to see Mr McElhill alive in the burning house.

Mark McGlynn and his brother had rushed to help the dying family.

Mr McGlynn told how he climbed a ladder outside the house to the first floor and saw Mr McElhill inside, crouched by the window, staring blankly as they tried frantically to rescue him and his family.

"He wouldn't get on the ladder for me and there was no way I could get into the house. The flames were just beating past my head," he said.

Last night the bodies of the two youngest children were recovered from the ruins.