A report on Burma alleging mass murder and rape by soldiers is to form the basis of an appeal for legal action against the military government there.
Burma's Karen people are seen as being particularly at risk
UK members of parliament and human rights groups are meeting to publicise the dossier compiled over five years by human rights researcher Guy Horton.
He made secret trips into the jungle to collect video and other evidence of attacks on ethnic minorities.
Burma's embassy in London has so far declined to comment on his findings.
The 600-page report, which was partly funded by the Dutch government, is based on interviews and documents compiled during numerous undercover trips to central Burma.
It also cites Burmese military communications intercepted by Thai intelligence officers.
The report accuses the Burmese army of destroying villages in the east of the country and forcing survivors into labour camps.
'Little girls raped'
Government soldiers are said to routinely use torture as a weapon, along with the rape of girls as young as five.
Mr Horton told the BBC he had video of "villages in the process of being burnt down", the mass slaughter of animals and "numerous" people being murdered.
"It shows one particular massacre of 10 people," he added.
During one four-week visit, almost every village he saw had been burned to the ground.
Villagers told him of soldiers throwing babies onto a fire during one raid.
Mr Horton claims his findings amount to genocide and he is calling on the international community to step up sanctions against Burma.