Here's a quote I dug up from Nebulus.org.
Likewise, scholars say they have laid to rest the notion, made popular in
the 1950's by the Norwegian explorer Thor Heyerdahl, that the original
people were Indians from South America. He thought he saw similarities
between Pre-Columbian Peruvian and Easter Island architecture. To make his
point that such contact was possible, he sailed westward from Peru in a reed
raft named the Kon-Tiki.
Linguistic, cultural and genetic evidence, most anthropologists agree, shows
that the people of Rapa Nui were Polynesians. Their language is Polynesian,
though it has changed so radically as to indicate an early separation from
the home culture and centuries of isolation. The few surviving examples of
ancient writing are in a script that has yet to be deciphered. The statues
and other artifacts bear a Polynesian imprint, and in 1994, the DNA from 12
Easter Island skeletons was found to be Polynesian.
THE SETTLERS Polynesians Found Isle Next to Nowhere
The first settlers apparently arrived from the west by canoe sometime
between A.D. 400 and 750. This was a time of epic voyages of Pacific
settlement. The migrating Polynesians, originally from Southeast Asia, had
reached Tahiti and the Marquesas islands by 300 before going on to discover
and occupy Hawaii and New Zealand.