The work carried out by Seddon’s engineers is being looked into as part of investigations being conducted by the fire brigade, the HSE and housing landlord West Housing Trust.

G&J Seddon had been refurbishing the kitchen of Marie Burns in the days leading up to the explosion in Irlam. It has emerged the gas pipe to the pensioner’s home, on Merlin Road, had been disconnected and re-connected three times in as many days.

The Bolton construction firm has said the work was done by a professional Gas Safe-registered engineer.

The blast was sparked on Tuesday morning when the 76-year-old switched on her cooker to make breakfast.

Fifteen people were injured, including 73 year-old Marie Burns who suffered 30% burns. Three homes were flattened in the blast, although as many as 10 may need to be rebuilt.

Over the weekend many residents were allowed to return to their homes once checks had been conducted by a gas inspector and a surveyor.

Tim Doyle, chief executive of City West, said: “Meetings are taking place with the 40 or so households that will be displaced on a longer-term basis to find out their medium and long-term aspirations.”

Managing director Jonathan Seddon said: “Our thoughts are with all the people that were affected by the incident in Irlam.

“We are giving our full co-operation to the authorities as they work to discover the cause. We can confirm that those working on the contract were all suitably qualified personnel.”