A British scientist's phone mysteriously "turned on" 24 hours after she vanished while out running on an idyllic Greek holiday island, it is reported.
and, when she didn't return to her room, her devastated partner raised the alarm.
Now her sister Jena Christopher claims her phone's signal began pinging yesterday.
Police aiding the search in Ikaria have found blood stains on a bedroom pillow in the hotel room Dr Christopher was sharing with her 38-year-old boyfriend, according to reports.
He said these were caused by a nose bleed Dr Christopher suffered on the night before she vanished.
The room has now been sealed off by police.
And local media says a hotel maid has told local media she heard voices the night before Dr Christopher went missing and thought the couple might have slept in separate beds.
"I heard some voices last night. When I checked in the room, I found that there was a sheet spread on the bedroom sofa, which may indicate that the couple was sleeping in separate rooms the previous night," Theodori Theodorakis told Sigmalive .
The scientist's sister Jena Christopher wrote on Facebook : "If you have her phone number please DO NOT call her. As this will drain the battery and the police are trying to use her phone to find her location."
Police had considered shutting down a phone mast on a neighbouring island as they sought a clear signal from the mobile, it is believed.
Dr Christopher, who was born in London and educated at Oxford University, arrived on the island on Saturday for a short break with her partner.
They were due to return to the UK on Monday.
But now fire crews, volunteers and even a naval helicopter with thermal imaging have been drafted in to help with the search in Ikaria.
Dr Christopher went out for a jog up a hill in a rocky part of the island on Monday.
Her partner told Protothema News said she promised she would be careful.
"I can't go fast, I'll be back slowly, don't worry," he claims she told him.
Dr Christopher works as a researcher with the European University Cyprus in Nicosia.
She works to "develop our understanding on the evolution of galaxies, by fitting models to data collected from telescopes and satellites," according to an online profile.
A Foreign Office spokesman said: "We are assisting the family of a British woman reported missing in Ikaria, and are in contact with the Greek authorities who are conducting the search for her."
