Missing US scientist Suzanne Eaton was last seen on the Greek island of Crete on July 2.
CNN  — 

Greek authorities are hunting for an American scientist who has gone missing on the island of Crete and was last seen six days ago.

Suzanne Eaton, a 59-year-old biologist at the Max Planck Institute at Dresden University in Germany, was attending a conference at the Orthodox Academy in northwest Crete, where she was seen on July 2.

She is believed to have gone for a run when she went missing, according to a Facebook page called “Searching for Suzanne,” which was set up by her family.

All of Eaton’s belongings remain in her room, including her passport, wallet, phone, cash and cycling shoes. However, her running shoes are missing, according to the page.

“Due to the rough terrain and extreme heat, we believe the most likely possibility is that Suzanne may have either become overheated and looked for shade or that she may have fallen,” a post on the Facebook page says.

Eaton is a mother of two sons and the wife of British scientist Tony Hyman.

Her employer, the Max Planck Institute, reiterated in a statement online that all theories were “speculative” and that the only known fact is that Eaton was last seen at the conference on Tuesday afternoon.

While it acknowledged that the “most likely” scenario was that she had gone for a run, the institute added: “There are many observations that challenge such a theory, including the heat of the day suggesting that a swim would have been more attractive.”

“As well as being a leading scientist in her field, Suzanne is a strong athlete, runner and senior black belt in Tae Kwon Do,” the statement added. “If anyone can find her way out of a difficult situation it is Suzanne.”

Max Planck Institute said in a post on Facebook that Eaton’s friends have offered a €50,000 ($56,000) reward for anyone who can provide any information about her disappearance.

By Monday afternoon, the Searching for Suzanne campaign had raised more than $30,000 to pay for further search and rescue teams in Crete. The campaign is also asking Facebook users to scour through online images in order to help locate the missing scientist.