Police investigating a suspected gas explosion in Shaw, near Oldham, which killed two-year-old Jamie Heaton, have released a plumber on bail.
Officers believe the 32-year-old man recently worked on a boiler at the property and he was being held on suspicion of manslaughter.
He was bailed by Greater Manchester Police late on Thursday until August 9 pending further inquiries.
Number nine Buckley Street was destroyed in the blast at 11.15am on Tuesday, as was a significant part of the house next door, number 11, where Jamie was watching TV in the front room.
Officers are still waiting at Wythenshawe Hospital to question 27-year-old Andrew Partington, who was seriously injured in the explosion.
Mr Partington moved into number nine six weeks ago with his partner and her five children.
Detectives are investigating reports that the couple were involved in a domestic incident on the night before the blast, which led to his partner and the children moving out.
During a news conference at the scene, Assistant Chief Constable Steve Heywood said Mr Partington was recently arrested for assaulting his partner.
"Some four to five weeks ago there was a domestic incident at that address and as is our policy robust action was taken," he said.
"Mr Partington was arrested and he was taken through the court system where he was given a conditional discharge by the magistrates' court.
"It is obviously a matter of speculation in the community and in the media and it would be common sense for us to pursue that line of investigation."
The owner of the destroyed house, local businessman Iltaf Hussain, told Sky News on Tuesday the boiler was newly-fitted when he let the property to Mr Partington and his partner, and was checked last week after problems were reported with the heating.
Meanwhile some residents who were moved out of the damaged area are being allowed to return home as a clean-up operation gets under way.
The most badly-damaged homes are still being treated as a major crime scene, but the sound of power saws and hammers could be heard as blown-out windows are boarded up in adjacent properties.
"We are continuing to work very closely with the council, fire service and other agencies to support the dozens of residents evacuated from their houses after the blast," said ACC Heywood.
"We are eager to get these people back home as soon as possible, but this can only be done once homes have been fully assessed and we are sure it is safe for them to go back."
