Foreign carers are being exploited by British firms and forced to work 19-hour shifts without a break, union leaders warn.
Recruitment agents demanded excessive five-figure fees from some migrants in return for finding jobs in the UK, according to Unison.
On occasions, employees worked 80-hour weeks and were paid as little as £5 an hour - despite always being available for shifts and having money deducted from wages if they tried to leave.
The Expendable Labour report - highlighting their shocking treatment - reveals many paid extortionate rents for substandard accommodation.
Unison is calling for the Government to intervene to help foreign care staff who face deportation when firms go bust and act to stop employers exploiting them “on a grand scale”.
It also says a change in visa rules is needed so migrant care workers who lose their jobs are not sent home and are given time to find new jobs.
The report says: "These skilled, committed, and hard-working staff are treated as expendable labour.
"A working week of 80 hours or more has been reported to UNISON by some migrant care workers. Others have been made to do 19-hour shifts without a break and forced to be always available for work."
Home Office figures show 143,990 health and care worker visas were granted in the year ending September 2023, more than double the 61,274 for the year to September 2022, as the sector tries to fill a record 152,000 vacancies.
The top three nationalities on these visas are Indian, Nigerian and Zimbabwean.
Cases reported to Unison include a care worker who paid a recruitment agent in India £12,000 to “introduce” her to an employer.
Once in the UK, the nurse had to pay £700 a month in rent for a shared house without heating and with mouldy walls.
Another care worker from Nigeria paid around £7,000 to an agent, which included visa expenses, but said: “I’ve sold everything so I can’t return.”
A Filipino migrant made redundant and facing an uncertain future said: “We’ve been dropped like we no longer exist.”
Unison general secretary Christina McAnea said: “It’s all too easy for employers to exploit vulnerable care workers from overseas. They’ve come here to support those most in need, only to be treated as expendable labour.
“Ministers must stop being complicit in allowing this abuse to happen.”
In October, more than 100 migrant care staff were made redundant when their employer Beaumont Healthcare in Cambridgeshire handed back its contract to the council. One staff member from the Philippines fired on the spot said: “I came here because I was needed. Now that I need help, I’m getting nothing.”
A government spokesman added: “We do not tolerate abuse in the labour market and where we identify exploitative practices are being undertaken by sponsors we take action.
“This can include the revocation of their licence.
“The Gangmaster and Labour Abuse Authority is working with other law enforcement agencies to identify illegal working and those found operating unlawfully will face prosecution or removal from the sponsorship register.”