For months, staff at Brook Medical Centre have been forced to perform intimate examinations in the freezing cold without heating or hot water.
Health workers say it is just one example of how unpaid bills and staff shortages have impacted patients at three GP practices in Northamptonshire, and accuse the partner-owners of putting people in danger.
GP services run by Dr Jalil Ahmed and Dr Jonathan Allinson have drawn criticism in south Wales recently, and the pair are set to resign from five surgeries there, claiming the contracts are unviable.
A spokesperson for eHarley Street, which provides remote management support to the partners, said they were "committed to delivering the highest standards of care" and described the allegations as "hearsay, fuelled by disgruntled ex-employees".
Dr Ahmed and Dr Allinson, both eHarley Street senior executives, hold NHS contracts for 24 GP practices in England and Wales.
They include Brook Medical Centre (Brook), Rushden Medical Centre (Rushden) and County Surgery (County) in Northamptonshire, which together have more than 20,000 patients and receive about £3.5m in funding from the Integrated Care Board (ICB).
The BBC has spoken to eight existing or former health workers at the three surgeries, all of whom asked not to be identified.
Many said there had been shortages of medical equipment such as speculums, emergency adrenaline, ECG patches, forceps and gloves due to "constantly unpaid invoices", which they claimed had resulted in some appointments being cancelled.
The BBC has seen internal emails that support most of the allegations.
Its understood a medical supplies company twice put a "stop" on the GP partners accounts because of overdue invoices amounting to more than £50,000.
A former employee at Rushden said that for several months last summer no butterfly kits were available to perform injections on children or people with fragile veins "so patients were being bruised with larger needles".
Staff members at Brook said the boiler was broken for more than a year leaving them with no heating or hot water.
"Everyone was in scarves and gloves, and we were struggling to weigh babies or do smear tests in the severe cold," one former worker said, "if we used fan heaters the electrics would trip during consultations."
"We had to clean up with sanitiser, and I couldnt open dressing packs because my hands were so numb," another said.
The boiler was replaced last month.
The BBC has seen various overdue invoices addressed to County since September, including a letter from HMRC requesting urgent payment of £4,500, a letter from a debt collection agency and a civil claim for £460 from a fire safety company.
Former staff claimed County had been a profitable surgery prior to being taken over in 2020.
One of those who spoke to the BBC said: "It doesnt make sense that doctors werent being replaced and nurses hours were cut afterwards – we became reliant on locums, and some werent coming back because they were owed money."
Since coming under new management, the number of permanent GPs at the Northamptonshire practices has reduced from seven to one.
"I dread to think what might happen," one employee said. "People are being put in danger and people will die this winter if things dont change."
Former staff at Brook said in recent months there were no qualified nurses to provide injections for patients with prostate cancer or do dressings on ulcerated legs; no asthma nurse; no nurse doing bloods and no secretary for a year.
"Babies were missing their vaccines because we couldnt fit them in, and it was heartbreaking to listen to the mums worrying."
"It was just banging your head against a brick wall," another worker said. "We were being threatened (by patients) daily and one of us was crying."
Several patients told the BBC they had been forced to register with a new surgery because it was "near impossible" to get an appointment.
James Hill, a councillor who represents Ecton Brook on the Conservative-controlled West Northamptonshire Council, said: "Its shocking, the state of it, and I think urgent change is needed before something terrible happens."
In a 28-page statement to the BBC on behalf the GP partners, eHarley Streets business operations manager Sam Clare said patient safety was their "top priority".
He said the amount owing to a medical supplies company across all practices was "a working debt" and "within normal parameters".
Responding to allegations about each practice he said: