The recent release of emails supposedly belonging to Hunter Biden, son of US presidential candidate Joe Biden, has "all the classic earmarks of a Russian information operation," 50 former senior intelligence officials say.
The New York Post last week reported on a batch of emails it obtained from a laptop supposedly left by Hunter Biden at a repair shop, suggesting that Joe Biden had used his former position as vice president to enrich his son.
Other news organisations have questioned the authenticity of the laptop's contents, which were provided to the Post by President Donald Trump's personal lawyer Rudi Giuliani.
In a letter published on Monday by news website Politico, ex-intelligence officials including several ex-CIA directors said there were a "number of factors that make us suspicious of Russian involvement."
It would be "consistent with Russian objectives" to create "political chaos" in the US, as well as to "undermine the candidacy" of Biden and help Trump, the officials wrote.
"For the Russians at this point, with Trump down in the polls, there is incentive for Moscow to pull out the stops," they continued.
"We want to emphasise that we do not know if the emails ... are genuine or not and that we do not have evidence of Russian involvement - just that our experience makes us deeply suspicious that the Russian government played a significant role in this case," they said.
Signatories to the letter included ex-CIA directors Leon Panetta, John Brennan and Mike Hayden, as well as former acting directors John McLaughlin and Michael Morell and ex-director of national intelligence Jim Clapper.
Australian Associated Press