In a preliminary report published late on Wednesday, the investigators did not say who they held responsible for the hack but said that both Britain and the United States were helping with their inquiry.
The comments attributed to Emir Sheikh Tamim bin Hamad Al-Thani on incendiary issues such as Israel, Iran and Palestinian Islamist group Hamas were one of the reasons cited by Saudi Arabia and its allies on Monday for imposing a diplomatic and economic blockade on Qatar.
Saudi Arabia, the United Arab Emirates, Egypt and Bahrain gave Qatari citizens 14 days to leave and closed their airspace to all Qatari flights. Saudi Arabia also closed Qatar's only land border.
"The investigation team confirmed that the hack was carried out using innovative technological methods by exploiting an electronic gap on the website of the Qatar News Agency," the report said.
"The team confirmed that the hacked file was installed last April, which was later exploited in the publication of the fabricated news on 24/5/2017, at 12:13 am (2113 GMT May 23)."
Moscow dismissed the allegation on Wednesday. "It's a stale claim and, as ever, there is zero evidence," said Andrei Krutskikh, a Kremlin adviser on cyber security.
Qatar says it intends to take legal action against those responsible.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections.