Zambia's ex-president Rupiah Banda on Tuesday pleaded not guilty to a charge of abuse of power linked to an oil contract signed while he was in office.
He was arrested on Monday after being questioned by investigators over his role in a deal with a Nigerian firm.
"No my Lord, I deny the charge," Banda told Magistrate Joshua Banda, who set the trial start date for April 3.
The former president was accompanied by his wife Thandiwe, and senior lawmakers from his party including opposition leader Nevers Mumba, who is also facing graft charges.
Banda's arrest came after parliament earlier this month lifted his immunity. The former leader who ruled Zambia between 2008 and 2011 was last week questioned about allegations of corruption, money laundering and fraud.
The 76-year-old lost power in an election to the current President Michael Sata.
Sata's government says Banda engaged in corrupt activities in the procurement of crude oil from a Nigerian firm, listed as the Nigerian National Oil Company in official documents. Nigeria's state oil outfit is known as the Nigerian National Petroleum Corporation (NNPC).
According to court documents, the procurement did not benefit the Republic of Zambia but Banda and his family.
The state also alleges that he "instructed his son Henry Banda to determine the destination of the funds which were proceeds of this contract... an act which is arbitrary and prejudicial to the interest of the republic of Zambia".
But Banda's lawyers claim the accusations are part of a ploy by Sata to silence opposition. Several former ministers and diplomats from Banda's administration have been arrested under Sata's anti-corruption crusade.