A horrific new clue may have been spotted on a toddler's finger after she was found wandering outside a church when her mother went missing.
Tahnee Shanks had been staying in a holiday resort in the tourist hotspot of Cancun when she vanished a month ago.
The 32-year-old Australian had travelled there with her estranged husband Jorge Astudillo and their daughter Adelynn, two, from their home in Merida on May 1.
Tahnee went missing the following day before Adelynn was found wandering barefoot outside Parroquia San Miguel Arcangel Church in Canun at around 9pm.
Since being reunited with her family in Brisbane, they have claimed an image taken of the little girl the night Tahnee went missing appeared to show blood on her little finger.
Despite this, they say there are no signs of injury or any marks in the bloodied spot - which could indicate the blood is in fact not her own.
Tahnee's brother, Daniel Shanks, told the Daily Mercury: "A detail we feel is critical to the investigation is a photograph taken of Addy outside the church which has gone viral includes a vital clue.
"We have asked investigators if this was reported or documented when addy was taken into custody and if the clothes she was wearing have been DNA tested."
It is feared Tahnee's disappearance, as well as husband Jorge who is also a missing person, could be a result of possible links to the Mexican cartel.
CCTV footage from the night she disappeared showed Tahnee, Jorge and Adelynn leaving the hotel together before passing a road toll out of town in their white 4WD just before 12pm.
Their car then made a U-turn 20km from their hotel before taking a detour down a different road.
Tahnee's phone then pinged as it travelled near to a supermarket, which is the last known contact she had, at around midday.
Hours after Adelynn was found, Ms Shanks' car was discovered burnt out 40km south of Cancun. Police have since launched a missing person investigation.
Adelynn was found by tourist Carlos Santos, who said another man pointed her out and left promising to go look for her parents - but never returned.
In another unnerving revelation, the investigation found Tahnee had sent a message to a friend moths before, telling her to remember her husband's name.
The eerie message read: "I know this is gunna sound weird but keep (his) name.
"Jorge Luis Aguirre Astudillo! Just in case anything happens to me they can go after him.
"Not that anything will! But I just want to keep that as a backup."
Adelynn's godmother Nikita Weller claimed her friend Ms Shanks confided in her about her fears about her husband.
The couple had recently separated after Ms Shanks found out he had an affair and booked a flight to return to Queensland with Adelynn.
Ms Weller said: "She found out he was into some shady stuff. She didn't say what.
"But it scared her enough to want to come home. She just said he was into shady stuff and she was scared and that was it.
"I told her: 'I think you need to come home. I think this is it, it's time you've got to come home somehow'."
Her desperate brother has offered a one million peso reward (A$70,000) for information on his sister's disappearance, despite police advising him against such a move as it could generate swathes of false information.
Tahnee's family say they are holding out hope that she is still alive, but there is still an eight-hour window on the evening of May 2 that remains unexplained.
