Zambian officials stepped up their investigation into ex-president Rupiah Banda's business dealings Thursday, questioning him about a Lusaka land deal.
In allegations unrelated to a court case for graft set to resume Friday, Banda was questioned in connection with a 198-hectare plot of residential land owned by an Egyptian investor.
"Banda has today been questioned in connection with the acquisition of Baobab land," Namukolo Kasumpa, spokeswoman for the investigators, told reporters refusing to give details.
The plot of land in the southern part of Lusaka -- earmarked for the construction of houses, a shopping mall, a hospital and a school -- is registered under the name Bantu Capital Corporation.
Banda's alleged connection to the deal is not known.
He was questioned for just under two hours.
Banda's supporters say it is just another example of the authorities harassing the former president.
He was arrested last month after lawmakers lifted his immunity from prosecution, which he is fighting in a separate court battle. His trial is due to open on Friday.
He faces a maximum of five years in prison if found guilty of stealing a Nigerian crude oil contract to benefit himself and his family while in office.
The case has prompted outcry in Zambia, with Banda supporters accusing the government of President Michael Sata of embarking on a political witch hunt.
The land allegations were not among the charges against Banda that were presented to parliament by Justice Minister Wynter Kabimba.
Kabimba alleged that Banda, while president in the copper producing nation between 2008 and 2011, had engaged in corrupt activities in the procurement of crude oil from a Nigerian firm.
He was also accused of funnelling taxpayer cash into his election campaigns.
He left office after losing to rival Michael Sata in elections lauded as a model in peaceful handover of power in Africa.
Since then, Sata has rolled out an anti-corruption drive that some have seen as a move to silence dissenting views.