Guatemalans who were deliberately infected with syphilis or gonorrhoea in medical tests in the 1940s are suing the US government for compensation.
Hundreds of Guatemalan prisoners, psychiatric patients and orphans were infected without their consent in a programme to study penicillin.
A class action lawsuit was filed by lawyers for the Guatemalans and their relatives.
The US apologised last year for the "reprehensible" experiments.
But lawyers said the Obama administration had not responded to a request for an out-of-court compensation settlement.
The tests were kept secret for decades, until a medical historian uncovered hidden records and made them public last year.
The study carried out by US scientists took place in Guatemala between 1946 and 1948.
Evidence of the programme was unearthed by Prof Susan Reverby at Wellesley College in the US.
The Guatemalan government of the day gave permission for the tests, she said.
But the people infected were unaware they were being experimented on.
In the experiments, researchers bribed care workers to let them inject their charges, while prisoners were encouraged to sleep with infected prostitutes.
Current Guatemalan President Alvaro Colom called the tests a "crime against humanity" when they came to light.