An inquiry is under way into whether two patients sent from a hospital to a care home had coronavirus.
Cheaney Court care home said it saw NHS paperwork saying patients sent to them from Kettering Hospital were Covid-free, but they later tested positive.
Lynda Goodman, whose husband Alex is a resident at the Desborough care home, has complained to the hospital.
Kettering Hospital's Patients Advice Liaison Service said it took "this claim very seriously".
The Local Democracy Reporting Service reported that the care home said it saw the paperwork when the patients were admitted between 25 May and 4 June.
The home said after being placed in isolation the residents then tested positive for Covid-19.
Mrs Goodman, who is unable to see her husband due to the on-going pandemic, said: "I still find it very hard to to believe that the people sent to Cheaney Court all were negative with tests done."
In an email to Mrs Goodman, Nicola McErlane from the Patients Advice Liaison Service said: "We take this claim very seriously, and we are investigating this concern thoroughly with the matron of the wards involved."
"It is hospital policy that we do not discharge any patient to a care home or nursing home if they have tested positive for Covid-19, until they recover and test negative," she added.
"It is disheartening to hear that when Cheaney Court carried out their own test that these patients then tested positive."
The email said the hospital was "unable to comment on how or when" the patients came in contact with the virus.