The court heard Wandelt had become obsessed with the “myth” that she was Madeleine and had been taken to Poland.
Giving evidence this week, McCann told jurors at Leicester Crown Court that Wandelt first made contact in January 2024.
Wandelt sent a message saying she had “so many flashbacks”, adding: “I know so many things. I don’t know if this is the real account for Amelie McCann but I can tell you my memories.”
Nadia Silver, prosecuting, said the messages from Wandelt included requests for a DNA test and alleged memories from their childhood.
“It is quite creepy – she is giving those details and trying to play with my emotions,” McCann said.
Asked how this made her feel, she said: “I felt uncomfortable about it because I don’t want to receive messages like that.
“It was quite distressing to see the messages. It’s a long message, and there’s a sound of desperation in her message which puts quite a lot of stress on me.
“It is quite disturbing that she’s coming up with these supposed memories even though she’s not Madeleine.”
Despite the persistence, McCann said she was not tempted to carry out a DNA test because she “always knew that she wasn’t Madeleine”.
McCann said she felt “guilty” for not agreeing to do a test, but Wandelt’s persistence “showed the lengths she would go to to try and get heard”.
The court also heard Wandelt’s efforts to contact McCann even extended to LinkedIn after she was blocked on Facebook, Instagram and TikTok.
“She did try to reach me in any way possible,” she said. “I thought that was quite extreme reaching out to me on a job platform.”
McCann said she also received a number of social media messages from Wandelt’s supporters.
She said: “There were people messaging me about Julia and saying, ‘not to be rude, but out of interest why aren’t you doing a DNA test?’, that sort of thing.”
Her twin brother Sean did not give evidence in person, but instead wrote a statement which was read to the court by the prosecutor on his behalf.
The court heard Wandelt first messaged him in November last year on Instagram, telling him she was Madeleine and asking him why no one believed her.
He said the messages were “not threatening in any way”, but they “upset” him and he blocked her.
“I do not believe that she is my sister,” he said, adding that claiming to be Madeleine was “disrespectful”.
“Knowing that Julia has made those efforts to mum and Amelie with the messaging ... this of course makes me upset to think they have been upset, caused by Julia,” he wrote.
“I did not want anything to do with her,” he said.
Wandelt appeared in court alongside Karen Spragg, 61, of Caerau, Cardiff. Both women deny stalking.
The trial continues.
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