The Salvation Army has apologised after a joint ITV and Guardian investigation accused the Christian Church and charity of acting like a "rogue landlord".
Residents on a Salvation Army-managed estate in Hadleigh, Essex, said they had complained about "substandard" conditions for years.
One resident, Kerry Maher, reported rising damp and mould after moving into her home in 2014 but nothing was done to fix the problem.
Environmental health consultant Jeff Charlton told investigators, "People are being made sick or their health is deteriorating living in this property.
"There is a responsibility under the Landlord And Tenant Act that the landlord makes the home health and safety compliant."
Another tenant described feeling "neglected" and "forgotten about" after saying that a hole in the roof still had not been fixed six years after the problem arose.
Other properties are reported to have breached fire safety regulations, with independent consultant Steve MacKenzie describing one home as a "fire-trap" and accusing The Salvation Army of being "criminally negligent".
According to the report, 2019 Castle Point Borough Council threatened legal action against The Salvation Army in 2019 over conditions on the estate.
Local MP Rebecca Harris said she had held numerous meetings with The Salvation Army to rectify the situation but "they kept making promises that failed to materialise".
Responding to the accusations, The Salvation Army issued an "unreserved apology".
A spokesperson for The Salvation Army said: "It is clear that we let down the tenants of Seaview Terrace and Mount Zion and we are deeply sorry.
"Considerable refurbishment and improvement work is already underway. We have employed a contractor as a Project Manager dedicated to Hadleigh and will be employing a Building Surveyor on a permanent basis to focus on Hadleigh going forward."
