The UK's Prince Harry inadvertently gave Russian pranksters, who posed as Swedish climate activist Greta Thunberg, his phone number and personal email address, a media report said.
The pranksters, Vladimir Kuznetsov and Alexey Stolyarov, revealed on Tuesday that they posed as Thunberg's director using a fake email address set up under the name of Ueli Maurer - the then President of Switzerland, The Sun newspaper said in the report on Wednesday.
Under the heading "Call or meeting with Greta Thunberg", the pranksters, also known as Vovan and Lexus, sent the emails to Harry and Meghan's Hollywood PR team at the beginning of December 2019.
Harry used his own email address to reply on December 29, 2019 from his Canadian hideaway on Vancouver Island, where he had stayed with Meghan and baby Archie.
On January 20, Harry also replied to Greta via the Ueli Maurer address believing she was in Davos, Switzerland, meeting world leaders.
The Prince also called the two Russians on New Year's Eve and January 22 from his mobile.
Speaking to The Sun newspaper about the incident, Stolyarov said on Tuesday night: " His staff must have forwarded him the email. Probably the emails were transferred through many people before he got it.
"We were shocked when he emailed us. No one ever checked us out to see who we really were."
The lapse has shocked royal insiders, who were blaming the Sussexes' new Hollywood PR advisers.
"This is the whole reason why we were concerned with them taking on agents in Los Angeles who don't follow royal processes," The Sun quoted an insider as saying.