Corneille Nangaa, ex-head of DR Congo's electoral commission, announced on Friday in a hotel in the Kenyan capital that he was creating a political-military alliance with M23 rebels and other armed groups.
The move sparked an angry response from the Congolese government who warned Kenya of "consequences" for hosting him.
"Kenya strongly disassociates itself from any utterances or activities likely to injure the peace and security of the friendly Nation of DRC," Foreign Minister Musalia Mudavadi said in a statement.
Mudavadi said Kenya had begun investigations "to determine the identities of the makers of the statement and the extent to which their utterances fall outside constitutionally protected speech."
He defended the fact that the "freedom of the press is vouchsafed" in Kenya and anyone was free to engage the media without reference to the government.
President William Ruto later said Kenya had rejected DRC's request to arrest the opposition figures.
"We don't arrest people who have made a statement, we arrest criminals," Ruto told journalists.
"If anyone has committed any criminality, we will go out of our way to deal with them," he said.
'Unpatriotic behavior'
Nangaa, who was president of the electoral commission for the DRC's 2018 polls, said that at least nine armed groups, including the M23, had already joined him in his alliance for "national unity and stability."
The announcement came at a time when the political and security climate in the DRC is extremely tense in the run-up to December 20 presidential elections.
In recent months, a series of clashes between Nangaa and Congolese President Felix Tshisekedi have hit the headlines.
Nangaa justified the creation of the alliance as a response to the "weakness" of the Congolese state over three decades and its "inability to restore authority... throughout the country."
FILE - Corneille Nangaa, the president of the independent electoral commission (CENI), speaks to reporters December 24, 2018 in Kinshasa, Democratic Republic of the Congo.
But the Congolese government denounced Nangaa's announcement as "unpatriotic behavior," and vowed diplomatic consequences for Kenya for hosting subversive activities.
"Kenya owes us an explanation," Communication Minister Patrick Muyaya said on Friday evening.
Kinshasa swiftly summoned the Kenyan ambassador in the DRC on Saturday and also recalled its ambassadors to Nairobi for consultation.
Some seven million Congolese are currently displaced within their own country, mainly as a result of armed conflicts and insecurity, according to the International Organization for Migration.
After several years of dormancy, the M23 ("March 23 Movement") rebels took up arms again in late 2021 and seized vast swathes of the eastern province of North Kivu.
Western governments and the United Nations have said neighboring Rwanda has supported the M23, allegations Kigali denies.