The government was ordered to repay 1 million pounds to the victims of the trafficking after the Supreme Court ruled that cutting its support payments was unlawful.
There follows a successful challenge from two applicants, a 19-year-old asylum seeker and victim of sex trafficking, against the cuts.
Her case was supported by charities for victims of human trafficking.
In early March, almost two months before Savid Javid took office, the weekly amount of money paid to more than 1,000 potential victims of human trafficking was cut by 42%.
Their weekly allowance dropped from £ 65 to £ 37.75, but now the missing £ 27.25 per week will be reimbursed after the court judgment at an estimated price of more than £ 1m.
Mr Justice Mostyn stated that the government does not fulfill the obligations of the Equality Act 2010.
The judge had been told how the juvenile asylum seeker had fled persecution and heavy exploitation by the traffickers.
The reduction in payments was said to have damaged his mental health and put him at risk of getting back into the hands of traffickers.
Silvia Nicolaou Garcia, lawyer for the law firm Simpson Millar, who represented the teenager, said the payment cut is forcing her client into an "increasingly unsustainable and frankly inhumane situation".
"He could not afford the travel he needed to meet his lawyers, which he had to do on a regular basis, he had accumulated debts and he could no longer afford to buy clothes, groceries or mobile loans to keep him can get in touch with his professional support network or his friends, "she said.
"We hope that the lifting of the cuts and a back payment to cover losses will help create stability and, above all, security for him."
The other "K" complainant, who suffered from depression and post-traumatic stress disorder after the sex trafficking, said after the decision, "I was so weak because I could not perform the activities that had helped me before my money was cut.
"Now that I can afford to get back to my support network and activities, I'm hopeful for my future."
Liberal Democrat Internal Affairs spokesman Sir Ed Davey attacked the Prime Minister, who has long campaigned for the fight against modern slavery.
He said, "Theresa May rightly called modern slavery the great human rights issue of our time, but her government has cut support for victims by 40% and made them vulnerable to further exploitation.
"Now that the court has declared these cuts unlawful, the government must undo them and ensure that the victims receive the help they need to escape the terrible bonds of slavery."
A spokesman for the Interior Ministry said, "We accept the court verdict and will provide our response in due course."
The spokesman added that ministers are working to ensure that the victims of modern slavery receive the necessary support.