British Sikh couple Sandeep and Reena Mander have filed a legal case claiming they were advised by an adoption agency not to apply because of their "cultural heritage".
The couple said they wanted to adopt a child of any ethnic background but reportedly they were told that, as only white children were in need, white British or European applicants would be given preference, which means they were not likely to be selected.
Instead, the couple alleges that they were advised to try to adopt from India, reports the Guardian.
"Giving an adopted child - no matter what race - the security of a loving home was all we wanted to do," Sandeep Mander said.
"What we didn't expect was a refusal for us to even apply for adoption, not because of our incapability to adopt, but because our cultural heritage was defined as 'Indian/Pakistani'," he said.
Adoption agencies were allowed to prioritise on the basis of race in order to match children to likely parents of the similar ethnic background.
But the government has also said that a child's ethnicity should not be a hurdle to adoption.
The Manders are applying to Slough county court, seeking a declaration that the policy should allow them to adopt the child. They were being represented by the law firm McAllister Olivarius and their case is also supported by the Equality and Human Rights Commission (EHRC).
Yesterday, the law firm's senior partner, Ann Olivarius, told the Guardian that too little attention had been paid to the best interests of the children in need of adoption.
"It is very odd when you have children in great need and who are desperate for a home. This couple seems the best candidates for parenthood you would want to know.
"They do not see racial divides, they just have so much love in their hearts and want to raise a family."
To place them lower on the list than another family because of their background suggested that the authorities had "lost the plot, we have lost what is important", she said.
The Manders said they had been trying to conceive for about seven years, and had gone through 16 IVF sessions, before deciding to try to adopt.
They attended introductory workshops organised by their local authority, the Royal Borough of Windsor and Maidenhead, and its adoption agency, Adopt Berkshire.
They said their case was first taken up by Theresa May, who is their local MP, during her time as the home secretary.
"Mrs May was shocked and was very helpful. Her office wrote letters but nothing happened," Sandeep Mander said.