The 32 foreigners who were arrested last week in the Democratic Republic of Congo and accused of plotting against the government have been released.
Joseph Kabila (l) succeeded his assassinated father Laurent-Desire
The 32, comprising American, Nigerian and South African security staff, were ordered to leave the country but no charges were brought against them.
Some of them were working for Oscar Kashala, a presidential candidate.
The BBC's Arnaud Zajtman in Kinshasa says diplomats and many Congolese doubt there was ever a plot.
The three Americans left DR Congo on Saturday and the 19 South Africans on Sunday.
It is not clear whether the 10 Nigerians in the group have returned home.
Mr Kashala, an opposition candidate in elections scheduled for late July, is still expected to stand but has lost his private security contingent, our correspondent says.
Congolese Interior Minister Theophile Mbembe Fundu has said DR Congo would not conduct any further investigation into the affair, as the judiciary was not equipped for the task.
He said that the men's countries of origin would conduct further investigations, but diplomats have described this as a face-saving measure, and are convinced of the men's innocence, our correspondent says.
Many Congolese citizens are comparing the accusations to strategies used by former dictator Mobutu sese Seko to discredit his opponents.
Alex de Witt, chief executive of the Omega Group which employs the men, told the South African Star newspaper the arrests were the result of a misunderstanding.
"I felt like I was in [reality television series]Survivor," South African Chris Sauer told The Star newspaper as he arrived at Johannesburg airport on Sunday.
DR Congo's first multiparty elections in 40 years are currently scheduled for the end of July.
Last week, the defence minister warned Congolese politicians that they should not have more than 25 bodyguards, amid pre-election tension.
Anneke Van Woudenberg of Human Rights Watch told the BBC the growing reliance on private security firms is symptomatic of increasing insecurity in Kinshasa.
A United Nations peacekeeping force of nearly 17,000 troops - the world's largest - operates in the country and is being augmented by a 1,500-strong European Union rapid reaction force over the election period.