The carcasses were discovered by a drone being used to investigate how the first six elephants plunged to their deaths at the Haew Narok waterfall, known as the Ravine of Hell, in Khao Yai national park in central Thailand, said Sompote Maneerat, spokesman for the national parks, wildlife and plant conservation department.
Two surviving elephants were trapped at the waterfall for hours before national park officials saved them, and fed them pineapples, bananas and sugar cane covered in supplements.
The 772 square mile Kao Yai National Park is believed to have around 300 wild elephants as well as other wildlife.
He said officials were only able to spot the additional bodies of elephants after the sky had cleared up on Monday. Five other elephants were thought to have jumped into Haew Narok Waterfall to try to save the baby.
Only two elephants in the herd are known to have survived the 200-metre (656.17-foot) fall in Thailand's mountainous northeast on Saturday, officials said.
Park rangers lowered food laced with supplements to the stranded animals to help them regain strength and climb back into the forest. Efforts are also underway to prevent similar incidents from happening.
According to the Bangkok Post, the new death toll makes it one of the biggest losses to Thailand's elephant population in recent memory. The waterfall has been temporarily closed, the Guardian reports, and a net has been set up downstream to catch the elephants' bodies before they reach a dam. Around half of Thailand's 7,000 estimated remaining wild elephants live in captivity, where the vast majority are subject to conditions World Animal Protection researchers deemed "severely inadequate" in a 2017 study.
Khao Yai is Thailand's third-largest national park.