Sacrificial backpacker-maiden, Vat Phu, from loupiot.com
The earliest evidence of human sacrifice among the Khmers might be this stone crocodile at Vat Phu Champasak. Today it’s in Laos, but it’s a Khmer temple dating from the 5th century, the very dawn of the Khmer kingdom. (The current temple is from the 11th/13th centuries – more on Wikipedia).
Crocodiles keep turning up. Every time a funeral is held a white flag is flown nearby. According to legend the custom commemorates a magical crocodile who ate a princess. The king killed the croc and hung his hide up at the place where his daughter’s ashes were enshrined, which was the start of the custom. After a while crocs became too difficult to find, and so the flag is now used instead. This relates to human sacrifice because the princess’s hundred handmaidens were supposedly buried under the hundred columns of the temple (this post has slightly different details, and mentions sacrifices for bridges).
There’s a pretty well documented report of a royally-sponsored human sacrifice at Ba Phnom, a sacred mountain near Phnom Penh, in 1877 (a prisoner taken at the end of a brief insurrection, but not simply executed, as there were strong religious overtones). A neak ta (local spirit) called Neak Ta Krol was receiving sacrifices as recently as 1904 – I got the little I have on that from an encyclopedia called Asian Mythologies, entry on Cambodian earth deities by Solange Thierry, who’s a highly reliable source, but no idea where it ultimately comes from – shocked French administrators putting a stop to it, perhaps? Someone should ask them about the symbolism of the Eucharist – at least the Cambodians weren’t eating the victims.
Much more recently, there were rumours in the early 1970s that the government authorities were kidnapping children and burying them under the Japanese Friendship Bridge, which connects Phnom Penh to the north. The idea was that the spirits of the sacrificed children would protect the bridge from the Khmer Rouge. The story is in the Phnom Penh Post. The person telling the story says he didn’t believe it at the time – but interesting that such a rumour should even be circulating.
Seima stone showing the earth-goddess Torani (pronounced torr-nee). This stone is flat-faced, but the stone buried in the pits around the shrine hall is spherical. From Andy’s Cambodia.
And then of course there’s human sacrifice and monastic boundaries. When a monastery is being established or re-established, the shrine hall has to be marked off from the secular world. Eight sacred stones, called seima, are buried in pits at the eight compass points and half-points (north, south, etc). A ninth stone is buried at the centre of this space, directly in front of the main Buddha image – this one represents the god Indra, king of Meru and the gods (because good Buddhists do believe in Hindu gods). Nowadays these stones are just stones, albeit holy ones, but they are the size and shape of a human head.
If you’d like to learn more about human sacrifice around the world, with a focus on Europe and the British Isles, I recommend the blog which calls itself Bizarre History. In fact I recommend that blog for everything.