According to the outlet, the intruder, who apparently flew from Spain to the U.K. over the weekend, spent around 20 minutes walking around the gardens before going into the building, where Andrew was home at the time.
She was eventually held in the lobby after asking a staff member where Andrew was. When the police were called, she claimed she was engaged to the Duke of York, 61, even telling them her name was Irene Windsor. Maps of the Royal Lodge and other Royal Family residences were found in her purse, along with a key ring, "which had spikes on it and could be used in self-defense," a source told the outlet.
"That potential weapon apparently caused the police some concern," the insider shared. "It is being dealt with as a major security breach. Someone is for the high jump over this."
"She was apparently very smartly dressed, in suit trousers, a yellow blouse and peach jacket, and had her hair done up and full make-up," a source told the outlet. "She cut quite a glamorous figure and the guards were completely taken in by her.
"The woman demanded they pay her cab fare as she was a close friend of Prince Andrew, and they obliged before helpfully pointing her on her way towards the Royal Lodge," the insider added. "They had no idea this woman was a total stranger to Andrew and seemingly had a fixation with him."
"She was very confident and walked around like she owned the place," the source said. "To the staff member’s shock, the woman then claimed to be engaged to Prince Andrew and said she was there to get married to him. She said that was the reason why she had flown over from Spain a couple of days earlier."
A police spokesperson said: "Thames Valley Police were called to the Royal Lodge at Windsor Great Park on Monday morning to reports of a female trespasser."
"The woman, aged 43, was intercepted and arrested. She was subsequently de-arrested and has been sectioned under Section 136 of the Mental Health Act," they continued. "The investigation into the incident continues, but there was no risk to any individual on the site. Due to the female being sectioned, we will not be commenting further at this time."
After Andrew — who lives with his ex Sarah Ferguson at the Royal Lodge — stepped back from his royal duties in 2019, his security has been scaled back, but he still has Met Police personal protection.