Recently leaked audio recordings of controversial conversations between senior Egyptian officials have "no indications" of being fabricated, according to an analysis provided to British police, the New York Times has reported.
For several months, a number of recorded conversations have been leaked to the media, including one involving Egypt's President Abdel Fattah el-Sisi.
In the taped conversation, Sisi makes offensive remarks about some Gulf Arab countries, suggesting Saudi Arabia, the United Arab Emirates and Kuwait have more money than they need, and that Egypt should have a share.
The New York Times reports that if the recordings are accurate, billions of dollars may have been siphoned off into special military accounts outside the control of the civilian government.
The three countries provided key financial aid to Egypt after Mohamed Morsi was toppled as president in July 2013.
A separate recording, obtained by Al Jazeera in February, appears to reveal Mohamed Ibrahim, Egypt's interior minister, discussing how the government can crack down on protesters across the country, using everything from water cannon to live rounds.
After the first recordings emerged last year, Egypt dismissed them as fabricated.
On Tuesday, however, the New York Times reported that an analysis of the recordings - commissioned by lawyers for Morsi's Muslim Brotherhood - found there were "no indications that the recordings were fabricated by splicing together disparate statements out of context".
'Moderately strong evidence'
According to the US newspaper, audio forensics firm JP French Associates found "moderately strong evidence to authenticate Mr Sisi's voice on two of the recordings and the voice of a top general, Mamdouh Shaheen, on another".
The analysis will reportedly form part of the lawyers' evidence in a British criminal case against the leaders who orchestrated Morsi's overthrow in 2013.
Wafik Moustafa, chairman of the British Arab Network, a political organisation, told Al Jazeera the recordings showed Sisi was becoming "the problem" in Egypt, and would weaken his position in the country.
"The Egyptian media is starting to publish anti-Sisi stories; people are suffering because the economy is in very bad shape; and the propaganda is not working any more," he said.
"Sisi has depended on 1960s-style Nasserist propaganda, which does not work in 2015.
"It's embarrassing, but the most important thing is that public trust has been lost and there's a lot of criticism from people on the ground. ... The regime is crumbling, it's in a very bad state indeed."
Michelle Dunne, a senior associate of the Middle East programme at the Carnegie Endowment for International Peace, said the leaks have affected relations with the Gulf states.
"The power dynamic between the Egyptian president and the Gulf states has been shifting, in particular with the change in leadership in Saudi Arabia," she said.
"The Saudi leadership is more sceptical of Sisi. They're not going to drop him altogether but they're putting him through his paces a bit."
Source: Al Jazeera