South Africa's former chief of police Jackie Selebi has pleaded not guilty at the start of his corruption trial.
He resigned as Interpol president after being charged with having links to organised crime and accepting bribes worth 1.2m rand ($157,000, £98,000).
The BBC's Jonah Fisher in Johannesburg says his case is seen as a test of a much-criticised justice system.
He is a senior member of the ruling African National Congress and the trial could have political ramifications.
As he left court, Mr Selebi said: "I am ready to drop bombshells."
His lawyers said the charges were part of a conspiracy against him by the National Prosecuting Authority.
They said the NPA had offered criminals immunity from prosecution if they testified against Mr Selebi.
The NPA has previously been accused of being heavily politicised, especially in its prosecution of President Jacob Zuma.
During the case at Johannesburg's High Court, prosecutors will seek to prove that Mr Selebi, 58, received corrupt payments over a five-year period.
The South African Press Association says he stood solemnly in a grey suit as the charges against him - two of corruption and one of defeating the end of justice - were read out.
"I plead not guilty," he said.
At the heart of the allegations is Mr Selebi's relationship with convicted drug smuggler, Glen Agliotti, who is also accused of links to the murder of a prominent mining magnate.
Prosecutors allege that Agliotti paid bribes and gifts to the police commissioner in exchange for turning a blind eye to drugs trafficking.
Mr Selebi, who was South Africa's first black police chief, was a close ally of former President Thabo Mbeki, a bitter rival to Mr Zuma.
Corruption charges against Mr Zuma were dropped shortly before he became president after elections in April. He said those were part of a plot against him by Mbeki allies.
Mr Selebi was a political appointee and had no previous experience of policing when he was appointed as police chief in 2000.
When the allegations of corruption first surfaced, opposition parties accused Mr Mbeki of protecting Mr Selebi.
His contract was extended even after he had been charged with corruption.
The case has now been adjourned until Tuesday.