A software company caught up in the controversy surrounding the US's now defunct policy to separate migrant parents from their children has drawn more criticism.
Salesforce, which helps Customs and Border Protection (CBP) manage its activities, had pledged £1m (£770,000) to charities to aid separated families.
But one of the charities has now rejected the donation.
It said it wanted Salesforce to cancel its contract with CBP instead.
RAICE (Refugee and Immigrant Center for Education and Legal Services) said it could accept the offer of $250,000 only if Salesforce cancelled its contracts with CBP.
"When it comes to supporting oppressive, inhumane, and illegal policies, we want to be clear - the only right action is to stop," said Jonathan Ryan, the charity's executive director, in a letter posted on its website.
"The software and technical services you provide to CBP form part of the foundation that helps ICE [Immigration and Customers Enforcement] operate efficiently, from recruiting more officers to managing vendors.
"Your software provides an operational backbone for the agency and thus does directly support CBP in implementing its inhumane and immoral policies."
Salesforce chief executive Marc Benioff announced on Twitter on Wednesday the company had now donated $1m to organisations helping families that had been separated at the US border.
He later tweeted: "Salesforce always will be true to our core values. We don't work with CBP regarding separation of families.
"CBP is a customer and follows our TOS [terms of service]. We don't have an agreement with ICE. I'm proud of the men and women who protect and service our country every day."
Salesforce's involvement with CBP has previously drawn ire from its own employees, hundreds of whom wrote to the chief executive urging him to end the contract.
The letter, sent in June after President Trump reversed the family separation practice, read: "We recognise the explicit policy of separating children at the border has been stopped, but that simply returns us to a status quo of detaining children with their parents at the border.
"We believe it is vital for Salesforce to stand up against both the practice that inspired this letter and any future attempts to merely make this destructive state of affairs more palatable."