The former First Secretary Dwight Saragay was set free by Justice Roseline Korir, on condition that the money, with two sureties of a similar amount are deposited in court.
Saragay is also required to deposit his passport with the court to guarantee that he will stay in the country throughout the hearing of his murder case.
Saragay is accused of killing Fonseca who was found dead at her Nairobi residence in August 2012.
In October, the High Court in Nairobi declined to grant bail to Saragay with Justice Nicholas Ombija ruling that he should remain in custody until his case is concluded.
Saragay, who has pleaded not guilty to the charge of murdering the envoy applied for bail arguing that his studies in law at the University of Nairobi have been hampered by his detention.
He insisted that he was a law abiding individual who was ready to obey all directives given by the court.
However the prosecution through State Counsel Tabitha Ouya opposed his release arguing that Saragay who was a senior official at the Embassy was likely to intimidate witnesses most of whom are his juniors.