A set of 43 mysterious eggs were found on Dec. 20 in the sandpit of an Australian school yard, raising questions over where they came from, and with some experts believing they may have originated from a highly venomous brown snake.

Volunteers removed the eggs from a playground at St. Joseph’s, a Catholic elementary school in Laurieton, New South Wales. Twelve eggs were discovered the first day and then the entire sand pit was searched by volunteer wildlife rescuers, according to the Guardian. After three days, the number of eggs found in seven different nests totaled 43.

Wildlife rescuers Yvette Attleir and Rod Miller from the group FAWNA initially thought the eggs belonged to water dragons, a lizard that grows up to 3-feet-long. The rescuers then said they believed the eggs belonged to the deadly brown snake — one of the most venomous brown snakes in the world.

“I believed they were brown snake eggs due to the fact that they were seen in the area and that when I shone a light through the egg I saw a small striped baby snake,” Miller told the Guardian at the time.

But internet reptile enthusiasts who’ve looked at the eggs and evidence have cast doubt on the brown snake theory. On Tuesday, FAWNA issued a Facebook update about the eggs.

“Some experts far more experienced than our local handler have pointed out that the eggs can’t be brown snake eggs. When we found the eggs we carefully checked the eggs over and found that they contained what appeared to be snake hatchlings,” read the statement. “We were told was there were a couple of sightings of large brown snakes behind the area and all we could surmise is that they were brown snake eggs.”

Bryan Fry, a venomous animal specialist at the University of Queensland, also changed his mind about his initial assessment that they were brown snakes. He cited the fact that the eggs were buried and that there were so many meant that the most likely belonged to water dragons.

“I reckon they are indeed water dragon eggs,” he told the Guardian Tuesday.

FAWNA moved the eggs to nearby bushland and said that all but three eggs hatched. Without the animals from the eggs present, the group said it was impossible to determine where the eggs came from.

“We believe we did the right thing, we couldn’t tell what the hatchlings were, they could have been pythons, they could have been dragons, they could have been brown snakes,” FAWNA President Meredith Ryan told the Daily Telegraph. “There was one unviable pink blob with little eyes found, but we can’t be certain what species.”