Andrew Mountbatten-Windsor privately complained to Jeffrey Epstein about sexual assault allegations well after he claimed to have cut off contact with the convicted sex offender.
The former prince claims to have severed ties with the paedophile financier in late 2010.
But newly released documents from a US congressional committee reveal he corresponded with Epstein on March 4, 2011.
Using an email address titled "The Duke", the correspondence was in response to a list of questions sent by a reporter from the British tabloid The Mail on Sunday.
The queries included the allegation that the then-prince had sex with Virginia Roberts Giuffre in a London house in 2001.
The former prince responded to the list of questions by instructing Epstein to ensure a strong denial was sent to the newspaper.
"Please make sure that every statement or legal letter states clearly that I am NOT involved and that I knew and know NOTHING about any of these allegations," the message states.
"I can't take any more of this, my end."
Epstein responds to Mr Mountbatten-Windsor several hours later.
"Just got it two minutes ago … I ye [sic] asked g (Ghislaine Maxwell) lawyers to send a letter. Not sure, it is so salcisous [sic] and ridiculous, I'm not sure how to respond," he says.
"The only person she didn't have sex with was Elvis."
The exchange is more evidence that the banished prince continued to keep in contact with Epstein after he told the BBC's Newsnight in 2019 he had estranged himself from the sex offender after an infamous meeting with him in New York's Central Park in December 2010.
He had told journalist Emily Maitlis he was doing "a number of other things in New York" when "we had an opportunity to go for a walk in the park, and that was the conversation, coincidentally, that was photographed".
"By mutual agreement during that walk in the park, we decided that we would part company, and I left.
"I think it was the next day, and to this day I never had any contact with him from that day forward," he added.
Other evidence has since emerged that contradicts Mr Mountbatten Windsor's insistence that he broke off contact with Epstein in 2010.
Last month, The Mail on Sunday revealed another email exchange between the former prince and Epstein where Mr Mountbatten-Windsor declared the pair "are in this together".
The Mail emails — from February 2011 — also revealed he told Epstein to "keep in close touch" and hoped that they would "play some more soon".
Mr Mountbatten-Windsor's ex-wife, Sarah Ferguson, was also found to have continued contact with Epstein in 2011, describing him in a 2011 email as a "steadfast, generous and supreme friend to me and my family".
Late last month, Mr Mountbatten Windsor was stripped of his prince title by his brother, King Charles, and ordered to leave the royal lodge.
Mr Mountbatten-Windsor has repeatedly denied ever meeting Virginia Roberts Giuffre, who died by suicide earlier this year.
A civil settlement between Ms Roberts Giuffre and Mr Mountbatten-Windsor was finalised in 2022.
