Qatar says state news agency first hacked in April

Doha : Qatari investigators have said that a cyber attack which saw the publication of explosive fake news last month that helped trigger a crisis with Gulf neighbours was prepared in April.

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)."

CNN reported on Tuesday that US officials believed Russian hackers were behind the planting of the fake news.

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.