Zambian corruption investigators on Friday arrested a former minister on theft charges and recorded a statement from ex-president Rupiah Banda's wife in another probe, an official said.

The "investigative wings", a graft-busting unit set up by Banda's successor, Michael Sata, said Banda's mines minister Maxwell Mwale had been arrested and charged over the theft of 20 bicycles belonging to small-scale miners.

"I can confirm the arresting and charging of Mr Maxwell Mwale in connection with theft of 20 bicycles belonging to small-scale miners in Eastern province. He has been charged for theft by a public servant and he will appear in court next week on Wednesday," the unit's Charity Chanda said.

Chanda said the bicycles were worth 5.5 million kwacha ($1,050, 800 euros).

The unit also questioned Banda's wife Thandiwe on Friday in connection with the family's Mpundu Trust estate, a posh villa the Bandas are building in Lusaka's upmarket Kabulonga district.

"She cooperated with the law enforcement agencies and the investigations are still continuing," Chanda said.

Sata has been on an anti-corruption drive since taking office last September after beating Banda at the polls.

National police chief Martin Malama said Thursday that Banda's son Henry was running from the law following accusations of corruption in the sale of state fixed-line operator Zamtel to a Libyan company.