Bemba was sentenced in June to 18 years in jail on five charges of war crimes and crimes against humanity.
Judges will Wednesday deliver their verdict against former Congolese vice president Jean-Pierre Bemba (pictured) and four close aides accused of bribing witnesses in a bid to derail his landmark war crimes trial.
Prosecutors have alleged that from his prison cell the ex-rebel leader Bemba masterminded a network to bribe and manipulate at least 14 defence witnesses to lie during his trial at the International Criminal Court.
Bemba was sentenced in June to 18 years in jail on five charges of war crimes and crimes against humanity committed by his militia in Central African Republic.
Once the powerful leader of the Congolese Liberation Movement (MLC) and a wealthy businessman from the Democratic Republic of Congo, Bemba, 53, remains behind bars in The Netherlands and is appealing the sentence.
But in a separate case after a tip-off to the prosecutor's office, he was charged along with two of his lawyers, an MP from his party, and a defence witness of presenting fake documents to the trial and dealing out backhanders to secure false testimony.
It was the first such corruption trial in the ICC's history, and prosecutors said the allegations showed "how far the accused were prepared to go to hide their illegal behaviour".
Also in the dock are Bemba's lawyer Aime Kilolo, his legal case manager Jean-Jacques Mangenda, along with Congolese lawmaker Fidele Babala and Narcisse Arido, a defence witness.
All five have pleaded not guilty to more than 100 combined charges.
"Bemba had a lot to lose in his trial: his stature, his standing, his political power, the possibility of a successful presidential election, his freedom," prosecution lawyer Kweku Vanderpuye said in his closing arguments in May.
Prosecutors had laid out the evidence that Bemba and his cohorts sought to pervert the course of justice, he said, pointing to telephone recordings, records of money transfers, emails and texts which "captured" the men's words as their plan went into action.
"Mr Bemba was at its core. Mr Bemba directed it. He okayed, he approved, he authorised and he instructed the acts of the other participants," said Vanderpuye.
Kilolo allegedly "coached" witnesses about what to say on the stand in return for money. Mangenda is believed to have been aware, as Bemba's legal case manager, that Kilolo was allegedly bribing witnesses, and is accused of relaying messages between Bemba and Kilolo.
Babala, deputy secretary of Bemba's MLC party, allegedly handled money transfers including payments to Kilolo, Mangenda and Arido.
Arido, who was an expert defence witness on military operations in the Central African Republic, is accused of recruiting witnesses for the defence and helping to coach them.
The defence, however, argued that the telephone recordings had been misinterpreted and insisted there was nothing wrong in paying witnesses as the prosecution did.
Bemba's lawyer Melinda Taylor added that since he had been in detention he was "not in a position of power and had no effective access to information about what was going on the ground".
If the five are found guilty, a sentence will be handed out at a later date.