British Gas has announced it will stop using warrants to force entry into customers’ homes and install prepayment meters.
It comes after The Times reported that the energy giant had used debt collectors to "break into" the homes of vulnerable customers.
The newspaper sent a report undercover to work for debt collecting contractor Arvato Financial Solutions and accompany their agents.
The reporter said they witnessed the agents work with a locksmith to force their way into the home of a single father with three children and fit a prepayment meter.
It reported that the locksmith said: "This is the exciting bit. I love this bit."
Energy companies are able to apply for court warrants to enter homes and install prepayment meters if customers have fallen behind on their bills.
Customers must then top-up their meter in order to keep receiving their energy supply, or risk being cut off.
But these are more expensive than paying for direct debit - leaving families more at risk of falling further behind on their bills.
Centrica, the owner of British Gas, has now said it was suspending "all warrant activity" after the newspaper's article was published.
Centrica chief executive officer Chris O'Shea said, "Protecting vulnerable customers is an absolute priority and we have clear processes and policies to ensure we manage customer debt carefully and safely.
"The allegations around our third-party contractor Arvato are unacceptable and we immediately suspended their warrant activity.
"Having recently reviewed our internal processes to support our prepayment customers as well as creating a new £10 million fund to support those prepayment customers who need help the most, I am extremely disappointed that this has occurred.
"As a result, on Wednesday morning, we took a further decision to suspend all our prepayment warrant activity at least until the end of the winter.
"More broadly, there are clearly significant challenges around affordability and unfortunately, we don't see that changing anytime soon.
"We need to strike a balance between managing spiralling bad debt and being aware that there are those who refuse to pay and those who cannot pay.
“We think Government, industry and the regulator need to come together to agree a long-term plan to address this and ultimately create an energy market that is sustainable."
Energy regulator Ofgem has also announced it will launch an investigation.
A spokesperson said: "These are extremely serious allegations from The Times which we will investigate urgently with British Gas and we won't hesitate to take firm enforcement action.
"It is unacceptable for any supplier to impose forced installations on vulnerable customers struggling to pay their bills before all other options have been exhausted and without carrying out thorough checks to ensure it is safe and practicable to do so.
"We recently announced a major market-wide review investigating the rapid growth in prepayment meter installations and potential breaches of licences driving it.
“We are clear that suppliers must work hard to look after their customers at this time, especially those who are vulnerable, and the energy crisis must not be an excuse for unacceptable behaviour towards any customer - particularly those in vulnerable circumstances."
The Mirror has contacted Arvato Financial Solutions for comment.
A recent report from Citizens Advice found an estimated 3.2 million people could not afford to top-up their energy meter last year.
It said more than one in five prepayment meter customers cut off in the past year spent at least 24 hours without gas or electricity, leaving them unable to turn the heating on or cook a hot meal.
Just last week, Ofgem said it is to review the checks and balances that energy firms have around placing customers on prepayment meters.
It followed Business Secretary Grant Shapps ' demand that energy suppliers stop forcing financially-stretched households to switch to pre-payment meters.
