The Government Palace's press department denied the version outright, without further comments or details.
The alleged bribe would have been paid when Vizcarra was Moquegua region's governor, a position that he resigned to become the vice presidential candidate of neoliberal businessman and politician Pedro Pablo Kuczynski.
In March 2018, Vizcarra replaced Kuczynski after the former president resigned in the face of a corruption scandal.
The witness, whose name is kept confidential, testified before the Anti-Corruption Prosecutor German Juarez, who is investigating the activities of companies that for over 20 years have agreed to distribute projects for bribes.
"The million dollars was paid by the construction consortium formed by the companies Obrainsa and Astaldi, in exchange for the contract to execute the Lomas de Ilo irrigation project," the witness assured while adding that he was the one who provided documentation.
Among other details, the declarant added that Vizcarra asked Obrainsa Company in December 2013, to rent, with a charge of the pending bribe, a small plane to bring a Bolivian delegation from Lima to the port of the Moquegua.
Last Friday, the Attorney General's Office announced that the Peruvian president will be investigated when his term ends in July 2021 for the irregular hiring of the almost-unknown singer Richard Cisneros 'Richard Swing', who received a wealthy contract from the Culture Ministry.