As many as 18 people may have died as a result of contracting coronavirus at Weston General Hospital whilst they were there being treated for other conditions.
An investigation into an outbreak in May found the infection could have contributed to their deaths, and health bosses have now apologised unreservedly to their families.
The report also found that as many as 131 staff members at the hospital tested positive for coronavirus between 5 May and 24 May - with 81 of those showing no symptoms.
Dr William Oldfield, medical director at University Hospitals Bristol and Weston NHS Foundation Trust, said he recognised the impact the outbreak had had on patients.
He added: "During the investigation we identified 31 patients who have sadly passed away having contracted coronavirus infection whilst they were an inpatient in the hospital. A detailed review into each of these individuals was undertaken.
"We are already in contact with the families of these patients and have informed them of the outcome of the review. We have apologised unreservedly and have offered them support.
"For each family concerned we will undertake an investigation into the specific circumstances which led up to the death of their loved one. We will invite them to help inform the investigation to ensure that any questions they have are addressed."
The hospital stopped accepting new patients on to wards, or in its Accident and Emergency department, on 25 May to curb the spread of Covid-19 among patients and staff.
It reopened on 18 June.
The investigation, carried out by the trust, reviewed the clinical notes of everyone who was an inpatient between 5 and 24 May, who had either tested positive or became positive for Covid-19.
It, alongside independent Public Health England analysis, did not identify a single cause for the outbreak - instead it listed a number of factors which may have contributed.
the size and layout of the hospital
the number and configuration of beds
relatively small team sizes and the need to move staff between wards to provide safe staffing levels
the presence of both staff and patients who were asymptomatic but tested positive for Covid-19.
The report also found that the transmission of coronavirus between patients in the same bay or ward had occurred, as well as between staff moving from wards designated as Covid positive and negative.
Dr William Oldfield added: "A number of the recommendations from our investigation had already been completed as part of planning for the safe re-opening of Weston General Hospital in June 2020; appropriate zoning in line with national guidance; we have reduced the number of beds in the hospital to improve social distancing between patients; and we have made significant efforts to minimise staff movements across the hospital, while following the national guidance on the appropriate segregation of symptomatic and asymptomatic patients.
"In addition, we have introduced rapid turnaround coronavirus testing which enables us to know the COVID-19 status of a patient very early on in their admission and this, in turn, better informs bed-management decisions. This is especially important in the context of the relatively small size of the hospital. We have also reviewed how our data is reported to enable earlier detection of potential issues as they start to emerge and take any appropriate action.
"We will share the learning from this outbreak with our local partners and the wider NHS, in order to try to prevent, as far as possible, a similar situation occurring again.
"Finally, we recognise the hard work of all our staff who were doing everything they could to maintain high-quality care in an extremely challenging situation, and the impact the outbreak, after an unprecedented few months responding to a global pandemic, has had on them."