The document, titled "Perinchellur Chepped" (Peruncellur Inscriptions), was tracked by noted historian Dr Kesavan Veluthat after years of investigation.
Though the circumstances which led to the missing of the document from Kerala is yet to be ascertained fully, the British Museum authorities informed Veluthat that they received it from an antique dealer, he said.
"The copper plate was gifted to the Calicut university's History Department by scholar and antiquarian Chirakkal T Balakrishnan Nair in 1976. The document is now available in British Library," Veluthat, a professor of Delhi University, told PTI.
"Then I contacted the authorities of British Library. They generously sent the images of the record and answered all my queries. I visited the British Library subsequently and physically verified the artifact," he said.
The historical details of the document has been included in the "Brahman Settlements in Kerala: Historical Studies", a book by Veluthat published in 1978.
A rare document inscribed in early Malayalam script 'Vattezhuth', the "Perinchellur Chepped" has references about the then ruler Karumpattu Iraman Iravivarmmar. Inscribed on both sides of the plate, the record has two brief passages in Grantha script also.