Video report by ITV News Meridian's Derek Johnson
Mouldy ceilings and damp walls are plaguing the lives of tenants living in a block of flats in Portsmouth.
Footage from inside Windsor House shows walls covered in black mould and pipes which are leaking water onto the floors.
Ian Knight, who is registered disabled, has not been able to sleep in his bedroom since a damp problem occurred.
He's told ITV Meridian, issues with the building have been going on for several years.
He said: "I've been sleeping in my front room for three years now. Everyone is now more than happy to help me now I'm registered disabled.
"It is just within the last week or so that it has only come to light.
"Before that, no one cared to come and have a look."
Windsor House in Canal Walk is owned by one freeholder, with some individual flats also owned by him.
Other flats have been sold on long leases and then rented out, which means some residents have different landlords.
Leah Hardwick moved into one of the flats 18 months ago. She says within a month the bathroom began to leak, until the ceiling collapsed. Leah says despite the ceiling being replaced, problems have continued.
She said: "Every time the rain falls, it pours through onto the shelves, damaging anything that it touches.
"The back wall in the bedroom has also been leaking. No one should live like that. It's awful.
"It's gut-wrenching when you pay so much and this is what you receive."
Communal areas and a number of flats have been visited by officers from Portsmouth Council today (7 January) in response to complaints from residents.
Cllr Darren Sanders, Cabinet Member for Housing and Preventing Homelessness at Portsmouth City Council, said: "We share the community's concern at conditions at Windsor House. It's a privately owned block of flats and it looks to me like those responsible for the maintenance of it are not maintaining it. Several private tenants at the building have got in touch with our private sector housing team recently and we've been investigating their cases, liaising with their landlords or the managing agents when necessary.
"It's become clear that other tenants, although they may not have contacted us, are also experiencing serious problems.
"We have the power to issue notices to private landlords telling them to make repairs by a certain date. If necessary we can get work done ourselves and recover the cost from the landlord or owner. In some cases we can prohibit the use of a property."
Local councillors, who have been supporting the tenants, say the conditions in Windsor House are some of the worst they have ever seen.
Labour councillor Kirsty Mellor said: "I'm quite sure that the owner of this building would not be prepared to live in conditions such as these.
"We want to continue working with the residents and with council offices to ensure that the residents here get the support and help that they need. Ultimately, I think what we're going to push for is to bring the owner of this property to account."
The owner of the building, Todd Hyatt, told ITV News Meridian he was not aware that the flats were in that condition, and that no resident had reported problems.
Mr Hyatt said he is offering to place residents in temporary accommodation while their flats are stripped out and refurbished, and that he does not want any of them to live in unsafe conditions.
He said that 90% of the flats had been refurbished two years ago, and that he doesn't want residents to live in these conditions.
He continued, "We will definitely act on this and we want to make residents' lives better. We do not want them to live in these conditions."