The country estate already boasts the Millennium Seed Bank

The timber was seized by customs officers after the consignment of afromosia arrived in the UK without the required export documents from Zaire.

It has now been used to build a �2m centre at Wakehurst Place, Ardingly.

Andy Jackson, head of Wakehurst Place, said the Royal Botanic Gardens became involved over the implementation of plant conservation issues.

'Beautiful timber'

Conservation strategies are set out under the Convention on International Trade in Endangered Species - an international agreement to protect wild animals and plants from exploitation.

Mr Jackson said: "Working with Customs we carry out inspections of plant consignments to ensure conformity with the Convention.

"After seizure we negotiate the final use of the plant material and hence our use of this beautiful timber."

The wood was used to construct the end walls of the visitor centre which has a cafe and sells tickets, gifts and plants.

The estate is home to the �80m Millennium Seed Bank and Europe's first reserve dedicated to rare mosses, lichens, liverworts and filmy ferns which grow on the rare Sandstone outcrop at Wakehurst.