Switzerland has denied leaking information about the alleged involvement of Angola's president in a money-laundering scandal.
The denial comes two days after the Angolan president, Jose Eduardo Dos Santos, sent a letter to the Swiss authorities, accusing them of passing information to the French newspaper, "Le Monde".
The alleged leak concerned a joint Swiss-French investigation into money laundering and embezzlement.
Le Monde said last week that Dos Santos, together with his industry minister, Elisio de Figueiredo, jointly pocketed $40 million of a $774 million loan extended to Angola by Russia.
The paper further alleged that the transfer of money was handled through two French intermediaries via a bank account in the Swiss city of Geneva.
In a letter addressed to the 2002 Swiss president, Kaspar Villiger, Dos Santos accused Switzerland of "arrogance" and an "abuse of power".
The Angolan president also claimed publication of the information was part of a "defamatory campaign" by unnamed "international economic circles" to stop his country from receiving foreign aid.
Responding to the letter, the Swiss foreign ministry denied having leaked any information about the investigation, which is being handled by the cantonal justice authorities in Geneva.
"The letter [from Dos Santos] was indeed harsh," said Daniella Stoffel, spokeswoman for the Swiss foreign ministry.
"But we have already made clear to the Angolans many times that in Switzerland there is a very strict division of powers and there is no way the executive could try to interfere in judicial matters," she told swissinfo.
Stoffel said the Swiss authorities had been in contact with the Angolan president prior to the arrival of his letter last Sunday.
"He will have received a letter which is not exactly a reply to his... but it does [address] his concerns," Stoffel said.
"We believe our relations with Angola are good and...this judicial procedure taking place in Geneva should not cause problems on the bilateral level," she added.
swissinfo with agencies