An alleged Portuguese hacker has been named as the person who leaked the documents which revealed how Africa's richest woman made her fortune through exploiting her own country, and corruption.
Last week some 715,000 leaked documents revealed how Isabel dos Santos amassed a fortune of more than $2bn (£1.53bn), allegations which she denies.
The Platform to Protect Whistleblowers in Africa (PPLAAF) said it was given the documents by Rui Pint of a whistleblower website called Football Leaks.
PPLAAF chief William Bourdon said Mr Pinto was not politically motivated and wanted to expose activities that were illegal or contrary to the public interest.
His lawyers have repeatedly defended him as a whistleblower and in a statement to Reuters news agency said: "Without the immense Luanda Leaks revelations, made possible thanks to our client, the regulatory, police and judicial authorities would have done nothing."
Mr Pinto has been in detention since last year, awaiting trial in Portugal on charges relating to unauthorised access to data and attempted extortion. His football leaks uncovered alleged corruption taking place in professional football.
The leaks provided millions of documents which were used as the basis for media reports that made damaging allegations against England's Manchester City and France's Paris St-Germain.
These latest leaks show Ms dos Santos got access to lucrative deals involving land, oil, diamonds and telecoms when her father was president of Angola.
The documents show how she and her husband were allowed to buy valuable state assets in a series of suspicious deals.
Ms Dos Santos says the allegations against her are entirely false and that there is a politically motivated witch-hunt by the Angolan government.