There are fresh allegations of neglect at a hospital run by the same health board that runs the Princess of Wales Hospital in Bridgend.
Graham Lucas' mother in law Margaret Hoskins was neglected at Swansea's Singleton Hospital.
The hospital's own inquiry has revealed that her medical notes for blood tests were "inadequate", and at one point she was left without food and water for hours.
Mike Griffiths reports
Mrs Hoskins been treated at Morriston, Singleton and Gellinudd Hospitals - treatment that her family says was inadequate.
– Graham Lucas, son-in-law
More often than not they would come round with the medication and leave it by the bed, and then sign the chart saying she'd taken it.
And then Margaret would hide it, from me, saying that she'd taken it, which she'd done in the house, so I raised concerns with the nursing
The report said nurses at all three hospitals hadn't complied with hospital policy by not supervising Mrs Hoskins taking her medication.
It found nurses at Singleton Hospital failed to make sure that Mrs Hoskins, who was diabetic, was given food and drink when she went for a scan.
There were also 'discrepancies' in her blood glucose tests that the report said would need 'further investigation'.
The health board says it's now part of its wider probe into blood test records at its other hospitals.
– Abertawe Bro Morgannwg University Health Board
In addition, since last year, the Health Board has been carrying out monthly audits, and regular spot checks, of all blood glucometry testing on its adult acute wards and rehabilitation wards in all our hospitals to ensure that record-keeping is being properly adhered to
In statement today, the board says it's reminded staff about rules over medication, as well as providing food and drink.
South Wales Police have confirmed that they've received a copy of the report, which they are now reviewing.