Switzerland has denied Russian claims that it failed to provide sufficient information in a now closed corruption investigation involving top Kremlin officials.
The Federal Prosecutor, Valentin Roschacher, said on Tuesday that Russian investigators had been kept "constantly and thoroughly" informed and been given all the documents they had requested.
His comments came as Switzerland announced it had terminated legal aid to Russia on all matters involving the case.
The statement follows last week's decision by Russian prosecutors to close a long-running investigation into allegations that two Swiss firms, Mabetex and Mercata, had bribed family members and associates of the former Russian president, Boris Yeltsin, in exchange for lucrative building contracts in the Kremlin.
Russian prosecutors said the Swiss had failed to provide sufficient evidence that a crime had been committed.
But Roschacher said the "documents were swiftly passed on to Russian authorities when they requested them". He added that the Russians had failed to take into account some seized documents which were repeatedly offered to them.
Roschacher demanded that Russia return the documents and said they would be made available to the Geneva prosecutor's office, which is also investigating the case.
The Geneva prosecutor in charge, Bernard Bertossa, said he would decide early next year whether to continue his investigation. He is trying to determine whether Kremlin officials used Mabetex as a front for laundering the alleged bribes.
Bertossa described Russia's decision to cancel its investigation as politically motivated, telling a Russian newspaper that the move was evidence of "a double standard of jurisprudence... one for friends, one for opponents".
swissinfo with agencies