(CNN) The body of British scientist Natalie Christopher has been found in Greece after she vanished while out on a run on Monday, police said on Wednesday.

Her remains were found in a ravine approximately 20 meters (66 feet) deep, in a rough mountainous area of Kerame St. Kirikos in Ikaria, Greek national police tweeted.

A major air, land and sea search had been underway on the picturesque island for the British tourist.

Christopher, a 35-year-old astrophysicist, was visiting the island with her partner from their home in Cyprus but wasn't in their accommodation when her partner woke up on Monday morning, a close friend of Christopher told CNN.

Christopher's partner spoke to her by telephone and she told him she had gone out for a run, but when she hadn't returned after several hours and had stopped answering her phone, her partner reported her missing.

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