Guatemala threatens to file a class action lawsuit against the US government for intentionally infecting 700 patients with mental health illness and prisoners with two sexually-transmitted infections as part of medical experiments conducted between 1946 and 1948.
US authorities have until Friday to resolve the issue outside the court or face legal action, according to the BBC.
Attorneys Andres Alonso and Terrence Collingsworth who represent the Guatemalans have sent a written complaint to US Attorney General Eric Holder to settle the claims out of court.
"We have decided to create one opportunity to see if we can settle the issues presented in this tragic situation without involving the judicial process," the lawyers said
In October last year, President Barack Obama apologized to Guatemalan President Alvaro Colom who accused the US of "crimes against humanity."
The tests that ran between 1932 and 1972 involved the inoculation of gonorrhea or syphilis organisms to hundreds of Guatemalans who did not know they were being used as experimental subjects.
Prostitutes with the disease were used to infect the unsuspecting subjects as the US scientists tried to evaluate the effect of the antibiotic penicillin in disease prevention or treatment. It remains unknown who and how many were treated or not.
The "reprehensible" experiment was disclosed by Wellesley College's Prof. Susan Reverby who said that the government of Guatemala gave the green light to conduct the tests.
Details of this report here.