President Mikhail Saakashvili has denied that Georgia`s armed forces committed war crimes during their attack on South Ossetia in August, BBC reported.
Evidence obtained by the BBC in the breakaway region suggests Georgia used indiscriminate force, and may have targeted civilians.
Witnesses said tanks had fired on an apartment block, and civilians were shot at as they fled the fighting.
UK Foreign Secretary David Miliband has raised the issue with Tbilisi.
South Ossetia and another region, Abkhazia, broke away from Georgia in the early 1990s, in the aftermath of the collapse of the Soviet Union.
Georgia`s attempt to re-conquer South Ossetia triggered a Russian invasion and the most serious crisis in relations between the Kremlin and the West since the Cold War.
The BBC recently undertook the first unrestricted visit to South Ossetia by a foreign news organisation since the conflict.
Marina Kochieva, a doctor in the regional capital Tskhinvali`s main hospital, told our reporters that she and three relatives were targeted by a Georgian tank as they were trying to escape by car from the town on the night of 9 August.
She said the tank fired on her car and two other vehicles, leading them to crash into a ditch. The firing continued as she and her companions lay on the ground, she added.
Georgy Tadtayev, a 21-year-old dental student, was one of the Ossetian civilians killed during the fighting.
His mother, Taya Sitnik, 45, told the BBC he bled to death in her arms on the morning of 9 August after a fragment from a Georgian tank shell hit him in the throat as they were both sheltering from artillery fire in the basement of her block of flats.
Mrs Sitnik said she subsequently saw the tank positioned a few metres from the building, firing shells into every floor. Extensive damage to the five-storey block appeared consistent with her version of events.
Mr Saakashvili said: "We strongly deny... accusation of war crimes - but of course, we are very open for any kind of comments, we are very open for any kind of investigation.
"We called indeed for international investigation into [the] conduct of this war, into conditions leading to this war, into circumstances leading to this invasion."
He added: "Those areas which were under Georgian control - and they were not Georgian villages, they were basically villages mostly predominantly populated by ethnic Ossetians but they were affiliated with the Georgian government - were 100% destroyed.
"So, you know, there were certainly war crimes committed, certainly not by us."
Mr Miliband - normally a strong supporter of Georgia - told the BBC: "I think the Georgian action was reckless, I think the Russian response was disproportionate and wrong.
"And that is the series of events that have landed us where we are.
"On my visit to Tbilisi of course I raised at the highest level in Georgia, the questions that have been asked and raised about war crimes and other military actions by the Georgian authorities.
"We have acted in this without fear, without favour."
The BBC visit also confirmed the systematic destruction of villages inside South Ossetia that were inhabited by ethnic Georgians.
Some homes appeared to have been not just burned by Ossetians, but also bulldozed by the territory`s Russian-backed authorities.