A rare book that was gifted to a child despite being laced with a deadly poison has been discovered by librarians.

Leeds Central Library's copy of My Own Garden: The Young Gardener's Yearbook was published in 1855, the year it was gifted to a youngster.

But experts believe the toxic text owes its vivid emerald green colour to a dye containing arsenic, which can be lethal when ingested.

The toxin was responsible for more than 200 deaths in nearby Bradford in 1858 when sweets accidentally made with the toxin were sold from a market stall.

Senior librarian Rhian Isaac found the book while cross-referencing the library's collection against a global database from The Poison Book Project.

The project, started by the International Institute for Conservation in America, aims to find editions of historic books made using hazardous compounds and heavy metals.

Rhian added: “As a librarian, it’s always incredibly exciting to discover any sort of rare, or unusual book in our collection.

"But this project is also really important as it helps librarians across the world work together and understand how and when these books were made as well as what steps we can take to keep track of them and make sure they are safely stored and cared for.

“Amazingly, heavy metals were once quite commonly used in the production of books as a way to achieve what was considered a very aesthetically pleasing shade of green."

An inscription in the book, which contains tips for budding young gardeners, shows it was gifted to Caroline Gott by her father William in 1855.

Both were descendants of wool merchant Benjamin Gott, who once owned Armley Mills and whose family remained prominent local industrialists for several generations.

It became part of the Leeds collection when Beryl Gott left a large part of her own library, mainly early botanical books, to Leeds Public Libraries.

Rhian added: "Whilst people at the time were certainly aware substances like arsenic were harmful, they probably didn’t understand the many different ways they could be accidentally ingested.

“The fact that this particular book also once belonged to the Gott family means its story is also a part of Leeds’s history and, with some careful handling and storage, it can continue to be part of our collection for many years to come.”

The library said tests would be carried out on the book, which had been hid from visitors, to assess how much arsenic it contains.