Rwandan President Paul Kagame Sunday warned that "treason brings consequences", apparently referring to the country's former spy chief, found dead in South Africa.
The body of Patrick Karegeya -- a fierce critic of Kagame -- was found on New Year's Day in a luxury hotel room in Johannesburg where he had spent the past several years in exile.
Police, who found a bloodied towel and a rope in the room's safe, said a preliminary investigation indicated he might have been strangled and opened a murder probe. Karegeya's supporters immediately accused the Rwandan government of being behind his killing.
"If someone feels no shame in destroying what we have built over a period of time, I for my part will not feel shy of protecting what we have built," Kagame said at a prayer breakfast in Kigali.
"Treason brings consequences," he warned Karegeya's fellow dissidents and other former allies who have gone into exile.
"All those fellows would have been nothing if it wasn't for Rwanda," he went on.
"Anyone who betrays our cause or wishes our people ill will fall victim. What remains to be seen is how you fall victim," Kagame said.
Karegeya was the former head of Rwanda's external intelligence service and once a close ally of Kagame.
In 2004 he was demoted, then arrested and served an 18-month jail sentence for desertion and insubordination. He was stripped of his rank of colonel in July 2006 and he fled the country the following year.
Kagame's comments follow remarks Saturday by Defence Minister James Kabarebe.
"Ignore those making noise saying that someone was strangled with a rope in the seventh floor in a certain country," Kabarebe told a public meeting promoting reconciliation among Rwandans.
"If you choose to be a dog you die like a dog and cleaners will remove the trash and dump it where it is supposed to be so that it doesn't stink for others. Those that have fallen victim, its because they have chosen that path," Kabarebe was quoted as saying in local media.
The minister confirmed to AFP that he had made those comments, adding: "When someone like him dies ... we are not really bothered."
Kagame and Kabarebe argued that Karegeya and his allies were behind a series of bloody grenade attacks in Rwanda over the past several years.
A Rwandan court in 2011 sentenced Karegeya in absentia to 20 years.
Three other dissidents were handed similar sentences. All four were charged with "forming a terrorist group, threatening state security, undermining public order, promoting ethnic divisions and insulting the person of the President of the Republic".
Karegeya had denied being linked in any way to the grenade attacks.
Rwandan Foreign Minister Louise Mushikiwabo, earlier said in Twitter messages that Karegeya was a "self-declared" enemy of Rwanda.
"You expect pity?" she asked her followers in the days following his death.