The butaan lizard was thought to be extinct for more than a century
A university has apologised to a graduate student who lost his unique collection of rare lizard excrement when it was thrown away by mistake.
Daniel Bennett had been studying the butaan lizard for more than five years in the Philippines and was working towards a doctorate.
He had built up a large collection of faeces samples which were stored at Leeds University and then disposed of.
The university said Mr Bennett was still due to finish his PhD this year.
The 35kg (77lb) bag of excrement was thrown out during a clear-out in his lab.
The butaan is closely related to the Komodo dragon. One of the world's rarest reptiles, it was thought to be extinct for over 100 years.
Mr Bennett said he spent seven years of painstaking work searching the rainforest to find the faeces of the large and mysterious lizard.
He said the reptile was so shy that he studied what it ate through its droppings, rather than trapping or disturbing it.
The university said: "The loss of these samples was an unfortunate mistake.
"They were thrown away in error because they were in an unmarked bag.
"Lessons have been learned and protocols improved to ensure this cannot happen again.
"Mr Bennett is due to graduate with his PhD this year, subject to minor corrections to his thesis, unrelated to the loss of the materials."