Zambia's former First Lady Esther Lungu and her daughter Chiyeso Katete have been arrested over possession of properties suspected to be proceeds of crime.

The two were arrested on Thursday in the capital, Lusaka, alongside another close relative identified as Charles Phiri, authorities said.

Ms Lungu "failed to give a reasonable explanation" of how she acquired a $1.5m (£1.2m) estate in the capital, the state anti-drug agency said.

Former President Edgar Lungu said the family would challenge the charges in court.

The former leader has been accusing the government of victimising him and members of his Patriotic Front (PF) party to block his return to politics ahead of 2026 elections.

He recently claimed to have been put under house arrest over his heightened political activities although the government denied it.

Last September, his wife was arrested over corruption allegations, involving cases of theft of motor vehicles and title deeds, which she denied.

On Thursday, Ms Lungu, 66, was arrested on suspicion of fraudulently acquiring a luxurious real estate in Lusaka, the Drug Enforcement Commission (DEC) said in a statement.

It said Ms Lungu owned "15 white double storey flats" situated in State Lodge area of Lusaka's Chongwe town, "reasonably suspected to be proceeds of crime".

The exact date the property, owned jointly with other unknown people, was acquired was not clear but the DEC said it was bought between 2015 and 2023.

The DEC said her daughter was faced with additional charges of acquiring another three flats estate in Lusaka, suspected to have been bought fraudulently.

"Further, she was arrested for possession of 1 high-cost house, four chicken runs, and associated external works in the property," the agency added.

They were all released on bond, said Mr Lungu, adding that they were safe at home after being questioned by DEC officials for several hours on Thursday.

Another of Ms Lungu's daughters, Tasila, is facing separate but related charges, according to the DEC.

She has been ordered, through her lawyers, to appear at the DEC on Monday.

The accused persons did not comment on the allegations but in a brief statement, the former president said the family would challenge them in court.

It was not immediately clear if and when they will appear in court.

Mr Lungu announced a comeback to politics last October, prompting the government to withdraw his retirement benefits.

He had retired from politics after losing the presidency to Hakainde Hichilema in 2021.

After six years in office, Mr Lungu left the southern African country heavily in debt and with a precarious economy.

Several former ministers, government officials and members of Mr Lungu's family have been on the radar of Zambia's investigative agencies in an anti-corruption campaign launched by President Hichilema.

Mr Hichilema has vowed to recover all resources allegedly looted while Mr Lungu’s was in power.

Critics say the anti-corruption drive is politically motivated.