Wikileaks has released more than 19,000 emails sent and received by seven top officials at the US Democratic Party, illustrating an acrimonious split between the Democratic National Committee (DNC) and Hillary Clinton's former rival, Bernie Sanders.
Several emails, leaked by the anti-secrecy website in advance of Hillary Clinton's nomination next week at the party's Philadelphia convention, showed DNC officials scoffing at Sanders and his supporters, and in one instance questioning his commitment to his Jewish religion.
The documents, which were released on Friday, appeared to indicate how hard fought Clinton's primary battle with Sanders was. In one email, Democratic Party head Debbie Wasserman Schultz described a Sanders' representative as a "damn liar".
Other emails also detailed how donors are rewarded with access to parties and free tickets.
WikiLeaks said the 19,252 emails were part of its new Hillary Leaks series.
Republican presidential candidate Donald Trump pounced on the leaks as he tried to garner support from disaffected voters who feel Sanders - a self-described democratic socialist initially dismissed as a fringe candidate - was denied a fair shot at the nomination by the political establishment.
"Leaked e-mails of DNC show plans to destroy Bernie Sanders. Mock his heritage and much more. On-line from Wikileakes, really vicious. RIGGED," he tweeted on Saturday.
In a May 5 email exchange, DNC Chief Financial Officer Brad Marshall asked if someone could ask a person he did not name, presumably Sanders, about his religious belief in the conservative states of Kentucky and West Virginia.
"Does he believe in a God. He had skated on saying he has a Jewish heritage," the message said.
"I think I read he is an atheist. This could make several points difference with my peeps. My Southern Baptist peeps would draw a big difference between a Jew and an atheist."
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Amy Dacey, the Democratic National Committee's CEO, responded in all capital letters: "AMEN."
The Intercept news website quoted Marshall as saying: "I do not recall this. I can say it would not have been Sanders. It would probably be about a surrogate."
Referring to the contested Nevada convention, Luis Miranda, the DNC communications director, wrote in an email: "It's clear that Bernie messed up and that we're on the right side of history."
A May 21 email chain discussed Sanders' assertion in an interview that he would oust party chair Wasserman Schultz once he was elected to the White House.
Writing from a Gmail account that media reports said belonged to Wasserman Schultz, the chairwoman noted: "This is a silly story. He isn't going to be president.".
Neither the DNC nor Sanders' camp have responded publicly to the leaks.
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Sanders waged a feisty year-long battle against Clinton in the Democratic primaries.
Clinton clinched enough delegates to secure the nomination in early June, but Sanders did not concede defeat and endorse her until July 12.