A care home has been accused of putting commercial concerns above the interests of residents who were moved amid the coronavirus crisis.
Families claim the home was offered financial incentives by the NHS to take patients just released from hospital.
There has since been a Covid-19 outbreak at the site they were moved to, an MP said.
The care provider said it had "acted in the best interests of staff, residents and the wider community".
Ellen Linley, 90, has dementia and was a long-term resident at Newfield care home in Sheffield.
However, she has now been moved across the city to Westbourne care home.
Both sites are run by Palms Row Health Care, which confirmed it has had a number of coronavirus cases at both homes.
Mrs Linley's family have contacted Louise Haigh, the Labour MP for Sheffield Heeley, who referred the case to the Care Quality Commission.
She said: "I think questions need to be answered about the motivations for moving residents and whether it is financially beneficial for care homes to receive NHS patients over care patients.
"Care homes should be making sure that they put their existing residents first and they should be communicating clearly about the care and the service they are providing and exactly how and where it is going to be provided."
Palms Row Health Care said five patients had tested positive for coronavirus at Westbourne, with two deaths, four positive cases and nine symptomatic patients at Newfield.
The provider - which runs three sites in total - said it had a longstanding relationship with the NHS with an agreed allocation of beds at Newfield.
Managing director Nicola Richards said it was "absolutely incorrect" to say the decision to move residents was financially motivated.
She said: "We risk-assessed the crisis we are facing, looked across all three homes and felt that it was in the interest of permanent residents to move them from Newfield to the other sites.
"We can only apologise if it wasn't communicated as effectively as it could have been, however we are facing a crisis, the challenges are increasing daily and we are acting in the best interest of our residents at all times."