What you need to know:
- Kinshasa accuses Rwanda of backing the Tutsi-led M23.
- Despite denials from Kigali, independent United Nations experts and several western nations, including the United States, agree with Kinshasa.
Rwanda is casting a shadow over the Democratic Republic of Congo's upcoming presidential election, with arrests of prominent Congolese figures suspected of colluding with the country's neighbour.
Relations between the two Central African states have been dire since the late 2021 re-emergence of the M23 rebel group, which has captured swathes of territory in eastern Congo.
Kinshasa accuses Rwanda of backing the Tutsi-led M23. Despite denials from Kigali, independent United Nations experts and several western nations, including the United States, agree with Kinshasa.
While suspicions of collusion with Rwanda have long been a feature of Congolese politics, tensions have ramped up in recent weeks, ahead of a presidential poll scheduled for December 20.
Last week soldiers arrested Salomon Kalonda, an aide to one of Congo's leading opposition politicians Moise Katumbi, at Kinshasa airport.
Congo's usually furtive military intelligence branch held a rare news conference on Monday to explain that Kalonda had been in contact with both the M23 and Rwanda in order "overthrow the government".
Kalonda also stands accused of illegal possession of a firearm. He is due to face prosecution, the military intelligence agency said.
'Web of lies'
Moise Katumbi, a billionaire businessman and the influential former governor of Katanga province, is running in the presidential election.
Katumbi's "Ensemble pour la Republique" party has roundly rejected the accusations against Kalonda.
Party dignitaries in the DRC's second-largest city Lubumbashi -- Katumbi's stronghold -- told journalists on Tuesday that the authorities had spun "a web of lies sewn from thin air".
Government spokesman Patrick Muyaya has yet to comment on the substance of the allegations against Kalonda.
But last week, during a studio interview with France 24 television station, he said that Katumbi is the only presidential candidate who has not "clearly cited Rwanda since the beginning of the crisis".
Kalonda's arrest has echoes of other recent cases, which have seen the fall of presidential advisers and army generals.
In January, a former counsellor to President Felix Tshisekedi, Fortunat Biselele, was arrested for alleged treason and suspected links with Rwanda.
And in March, Congolese MP Edouard Mwangachuchu, who represents the Masisi area of North Kivu was arrested for alleged links with the M23.
The owner of a well known mining company, Mwangachuchu is currently facing trial in Kinshasa.
Other political players were felled by accusations of links with Rwanda last year.
Lieutenant-General Philemon Yav, who led the Congolese military operation against the M23 in North Kivu, was arrested in July 2022 on suspicion of high treason, and has been held in prison since then.
Francois Beya, a former special counsellor to President Tshisekedi in charge of security, was arrested in February last year. He was charged with conspiracy, but military judges granted him a temporary release from custody for health reasons.
Armed groups have plagued eastern DRC for three decades, a legacy of regional wars that flared in 1990s and 2000s.
But an ethnic conflict also emerged in western DRC last year, and has skirted close to the capital Kinshasa, prompting the Congolese government to speak darkly of a "black hand" directing the violence.
During a trip to China in late May, President Tshisekedi accused the political opposition of stirring up trouble in order to disrupt the elections. He also said he suspected that Congo's "horrible neighbour" Rwanda was implicated.