On Tuesday, Eleni Fotiadou watched in tears as the body of her daughter, Eva, was exhumed for forensic tests.

In a story which has gripped the national press, Ms Fotiadou refused to believe the official version that her daughter - a marketing student - had overdosed on heroin after her body was found in the port city of Thessaloniki last June with a syringe nearby.

She told the BBC: "My daughter was bruised from head to toe. Her face was so disfigured she was hardly recognisable. And there were finger marks on her throat."

Acting on an anonymous tip-off, she launched her own investigation, returning each day from her job as a lab technician to change into a short skirt and high heels and go onto the streets pretending to be a prostitute and drug addict.

Ms Fotiadou - dubbed "Mother Courage" by the Greek press - says she met and made secret tape recordings of people who knew details of the abduction and murder of her daughter.

She believes her daughter was beaten and raped before being injected with drugs to make her death seem like an overdose.

Eva was last seen alive when she left her sister on a park bench to go off and buy a drink.

Vice trade

Thessaloniki is a major centre for east European mafia gangs involved in the vice trade and a staging post on the route used by Balkan heroin smugglers.

Ms Fotiadou's supporters say that stories of her daughter being a drug addict were smears to divert attention from official incompetence and corruption.

The evidence she gathered was handed to the police who ordered her daughter's body to be exhumed.

The authorities have also ordered eight people to undergo questioning by a magistrate investigating the case.

However, the police say that some parts of Ms Fotiadou's story do not make sense, and that her grief has been exploited by people around her for publicity purposes.