Provincial assemblies in the Democratic Republic of Congo are voting for senators today in 24 of the country’s 26 provinces.
The election takes place amid unprecedented public allegations of corruption and vote buying.
At least seven candidates have withdrawn from the senatorial race in protest of the alleged corruption, accusing provincial MPs of demanding payments of sums as high as $50,000 (£37,723) in exchange for their votes.
On Saturday, Congo’s general attorney Flory Kabange Numbi wrote to the electoral commission asking it to postpone the senatorial vote so that police can investigate these allegations.
His request was not accepted by the electoral commission.
Its rapporteur told the BBC that even elected senators, if later found to have taken part in the alleged vote-buying saga, can still be investigated and prosecuted after the vote.
Provisional results are expected to be made public later this evening.
The Constitutional Court will have eight days to confirm results.
The provinces of Maïndobe and North Kivu, where elections were delayed due to security concerns and the ongoing Ebola outbreak, will elect their senators in May or June. Former President Joseph Kabila is already the first confirmed senator.
By law, his status as a former head of state guarantees him a lifelong seat in the Upper House of Parliament.
Senators wield considerable influence, and according to the constitution, the Speaker of the Senate would be the first in line to take over should the president become incapacitated or vacate the executive office.