Dipankar De Sarkar

London, Jan 20 Britain has laid claims to Nobel laureates Amartya Sen, an Indian citizen, and Venkatraman Ramakrishnan, an American of Indian origin.

The two were among "British Nobel Prize winners" who were hosted by Prime Minister Gordon Brown and his wife for a dinner at their 10 Downing Street residence, the British leader's office said.

Guests at the dinner Monday night, a celebration of winners over the past three decades, included last year's chemistry laureate Ramakrishnan and Sen, who won the 1998 Nobel for his work on welfare economics.

"British winners of the prestigious Nobel Prize have gathered at Downing Street to celebrate their achievements," said the Prime Minister's office.

Brown described Sen, Ramakrishnan and other guests as "the pride of our country".

"Britain was where the first novel was written, the theory of gravity was first formulated, and penicillin was first created to save millions of lives. All of you, the pride of our country, are heirs of that legacy who have nobly enlarged it. You stand on the mountaintops of our time, of human aspiration and achievement," said Brown.

But in his 'autobiography' on the Nobel website, where winners write about themselves, Sen says he is "exclusively an Indian citizen".

Ramakrishnan, born in Tamil Nadu and educated in Gujarat, is an American citizen who won his Nobel for his research conducted at a British laboratory.

The British prime minister's office did not comment on the apparent anomaly despite repeated requests, but a leading British academic said rivalling claims to Sen's nationality show just how valued he is around the world.

Lord Nick Stern, head of the India Observatory at the London School of Economics, said at least four countries lay claim to Sen: India, where he was born; Bangladesh, where he received his early schooling; Britain, where he went to university; and America, where he currently teaches.

"It's not hard to see why there are so many competing claims to Amartya," said Stern moments after the Nobel laureate had delivered a typically incisive lecture on child undernourishment to a packed auditorium Tuesday.

Stern said not only countries, but institutions too vied to claim Sen as their own. These included the Delhi School of Economics, the London School of Economics, Cambridge and Oxford Universities and Harvard -- places where he has taught.

Ramakrishnan said last year that his Nobel was a "much bigger deal" in India than in his institute -- the MRC Laboratory of Molecular Biology in Cambridge.

"In India I'm seen as the first in my field. In my institute, I'm just the 15th Nobel laureate," he said.

Other Nobel laureates at Brown's dinner included former Northern Ireland politicians John Hume and Lord Trimble, who shared the 1998 Nobel Peace Prize, Sir Tim Hunt, (2001, physiology), Sir Martin Evans (2007, medicine) and Sir John E. Walker (1997, chemistry).

Britain ranks top in Europe in terms of the number of Nobel prizes won, and is second globally only to the U.S.