Authorities are probing a crucial piece of evidence left behind in the abandoned World War II bunker in Greece where an American scientist was found dead last week, according to a new report.

Though no information about the nature of the evidence was revealed, investigators are confident it could be the key clue to help identify who killed 59-year-old Suzanne Eaton, a police source told ABC News.

Authorities are questioning at least 10 locals from the island of Crete, where Eaton had been attending a conference before she disappeared, the source told the network.

They took DNA samples for all persons of interest and have requested data records from local mobile phone companies, in hopes of identifying whoever left Eaton’s body in the bunker, according to the report.

DNA test results are expected to be available in a matter of days, the source told ABC.

Prime persons of interest include men with muscular builds — who would be able to overpower Eaton, an avid runner who held a black belt in Tae Kwon Do, the outlet reported.

Eaton appeared to have fought for her life against an attacker armed with a knife — and her body had substantial “defensive” knife wounds, a source told the outlet.

It was unclear whether Eaton was killed at the bunker or attacked somewhere else and then left there, according to officials. Coroner Antonis Papadomanolakis told the network that her death resulted from a “criminal act” and that she died of asphyxiation.

Eaton, a mom of two from Oakland, Calif., was a molecular biologist at the Max Planck Institute in Germany.

Her body was found late Monday in the town of Chania in Crete, about five miles from where she disappeared while attending the conference, authorities said. Colleagues became concerned after she missed several sessions.

Her body was discovered bruised and covered with burlap in the cave, according to reports.