Update:
A 32-year-old man has been arrested on suspicion of manslaughter after the death of a toddler in an explosion in Oldham.
The man was taken into custody following two-year-old Jamie Heaton's death in Shaw on Tuesday.
The child died after what was believed to be a gas blast ripped through three terraced houses and reduced them to rubble.
National Grid has confirmed that the blast was not caused by a leak from one of its gas pipes and Greater Manchester Police have launched a "homicide investigation".
Jamie, who was killed while he watched television, was described by his family as "a happy, loving little boy... full of laughter".
Earlier his relatives visited the destroyed buildings and laid flowers at the edge of the police cordon.
In a statement the family said: "Jamie was a happy loving little boy - precious son to Michelle and Kenny and loving little brother to Jodie and Jack.
"Jamie's life was full of laughter. He loved going to preschool, playing with sand and water and going to the park. He touched the hearts of all who knew him and will be missed by all."
His mother survived the carnage after she momentarily stepped into the yard to hang out washing to dry.
Her husband and two other children were not at home and were spared serious injury.
On Wednesday detectives said they have "significant questions" for the boy's neighbour, Andrew Partington, who was seriously injured in the blast.
Mr Partington, 27, who is not related to the child, was taken to Wythenshawe Hospital with severe burns after the explosion, where police said he was "unconscious and sedated".
Assistant chief constable Steve Heywood, from Greater Manchester Police, said: "We've had information to suggest that it might not have been accidental, so we are treating it as a suspicious death and, therefore, a homicide investigation is being undertaken."
He said reports of a domestic argument on Monday night were being investigated.
Police say Mr Partington was alone in the house where the explosion happened.
Asst ch con Heywood said: "Obviously we want to speak to Mr Partington when he wakes up and he's currently got some colleagues with him from police."
Police confirmed another adult and five children live in the house with Mr Partington but were "in another town" when the explosion happened.
The massive blast flattened number 11 Buckley Street, where Jamie lived, and number nine, where Mr Partington lived. It is understood Mr Partington had only moved into the property around six weeks ago.
To give you an idea of the devastation, here is the house on google Maps:
http://goo.gl/maps/qtG0