A former psychiatric hospital graveyard in Tyrol, Austria is believed to contain the remains of euthanasia victims killed between 1942 and 1945 under the Nazi regime.
The remains of up to 220 people have recently been discovered and are set to be fully exhumed in March.
Archived hospital documents have shown that the death rate of the patients spiked towards the end of World War Two.
Despite the hospital not being officially part of the euthanasia programme, the recent discovery may shed light on the extent to which the principle was systematically adopted by psychiatric institutions.
Nazi Germany launched its euthanasia project, known as Aktion T4, in 1939, as a result of its policy to eliminate individuals whom it considered to have a “life unworthy of living.”
This included the mentally and physically handicapped, the elderly and the incurably ill.
It is estimated that some 275,000 men, women and children were murdered under the programme.
A state-owned construction firm unearthed the remains last week in the grounds of a former psychiatric hospital during routine excavation work.
Full exhumation of the graves is scheduled to take place in March, once the ground has thawed.
Government officials were shocked by the discovery, with Tyrol’s governor, Günther Platter, saying he was “deeply shaken.”
He has pledged to set up a commission of experts to investigate the find.
“There can be no cover-up. This dark chapter in our history must now be thoroughly examined”, the governor said.
Euthanasia, the killing of people deemed to have a quality of life no longer worth living, is illegal in the UK.
Voluntary euthanasia is legal in countries like Holland, where the rate of such deaths increased by 13 per cent in 2009.
The subject of euthanasia was in UK news a number of times in 2010.
In February, new assisted suicide guidelines were issued by Director of Public Prosecutions Keir Starmer QC, who said prosecutions were unlikely if the act was “motivated by compassion”.
In October, a small group of medics calling themselves Healthcare Professionals for Change, launched a campaign to weaken the law on assisted suicide, but any such moves are firmly opposed by the British Medical Association.
In November, a commission to investigate assisted suicide was launched, backed by pro-euthanasia group Dignity in Dying and chaired by Labour peer and former Lord Chancellor, Lord Falconer, who has previously tried to weaken the law on assisted suicide.
And in December, MSP Margo MacDonald attempted to introduce her End of Life Assistance Bill into Scots law, claiming widespread public support, but this was heavily defeated.