At a special awards ceremony in London, the museum was presented with £100,000.

The Ulster Museum, which reopened in October 2009 following a £17.2m rejuvenation, faced competition from museums across England, Scotland and Wales and last month reached the final shortlist of four, along with the Ashmolean Museum (Oxford), Blists Hill Victorian Town (Shropshire) and The Herbert Art Gallery and Museum (Coventry).

The competition involved an online public vote as well as a rigorous judging process led by broadcaster Kirsty Young.

Tim Cooke, director of National Museums Northern Ireland, said, "Rejuvenating the Ulster Museum in Belfast has been a deeply rewarding and purposeful experience coinciding with a remarkable period of change in Northern Ireland's history. The public appetite for the new space and for engagement with our collections has been huge - as evidenced by the record visitor numbers and the massive level of support for the public vote element of the Art Fund Prize."

The £100,000 prize will be spent devising a special programme, according to Mr Cooke.

He said: "We plan to devise a special programme designed to extend knowledge of, and engagement with, the Ulster Museum collections across art, history and science. Entitled the Ulster Museum/Art Fund Prize Programme, it will include partnership initiatives, internships, specific research, publications and web initiatives. The scheme will run for a two-year period."

Ms Young, head of the judging panel, said: "We were moved and invigorated by our visit to the Ulster Museum. Here is a museum that shows how much can be achieved, and one that is building a lasting legacy. We were impressed by the interactive learning spaces on each level that are filled with objects which visitors are encouraged to touch and explore, and by how the museum's commitment to reaching all parts of its community is reflected in the number and diversity of its visitors.

"The transformed Ulster Museum is an emblem of the confidence and cultural rejuvenation of Northern Ireland."

Since reopening, the Ulster Museum has become Northern Ireland's busiest visitor attraction with visitor numbers to date of over 420,000.