Daniel Bennett has threatened to take the university to court after it destroyed the material, produced by the rare Butaan lizard.

It had been painstakingly collected for his research project in the university's faculty of biological sciences.

His PhD was based on analysing samples he gathered in fieldwork in remote areas of the Philippines.

When he returned for his third year he found his desk occupied by another student – and his samples burnt by university technicians.

He said: "I was surprised to find my desk space occupied by another student. My personal effects had been carefully stowed in boxes, but there was no sign of my 35kg bag of lizard ****."

He said he had been offered £500 compensation, but had refused the money.

The reptile – a close relative of the Komodo dragon –- was assumed extinct for more than 100 years. Mr Bennett spent five years investigating its diet, numbers and behaviour by sifting through faeces found on the jungle floor.

He then won a scholarship at the university where he was paid to analyse more samples.

A university spokeswoman said Mr Bennett had received an apology and a full response. "He is appealing against this, so the matter is still active; we are unaware of any legal action.

"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."