The daughter of Congo's President Denis Sassou Nguesso is under investigation by the French police for corruption, the AFP news agency reports, quoting judicial sources.

Julienne Sassou Nguesso, along with her husband Guy Johnson, are being investigated for "money laundering and misuse of public funds", AFP adds.

This comes after the couple bought a $3.4m (£2.7m) house in an upmarket area in Paris. The police want to know where that money came from.

The investigation is part of a probe by French police into how members of the families of three African presidents - Congo, Gabon and Equatorial Guinea - have spent their money in France.

Neither Ms Nguesso nor her partner have commented on the investigation, but her lawyer is quoted by RFI as saying that he will try to overturn any indictment.