The world's oldest man, a retired chemist and parapsychologist, has died in New York City aged 111.

Alexander Imich's niece said he died yesterday at his home in Manhattan.

Karen Bogen, of Providence, Rhode Island, said she had visited him a day earlier. She said his health declined about two weeks ago and he did not recognise her.

Mr Imich was born in 1903 in a town in Poland that was then part of Russia. He and his wife fled after the Nazis invaded in 1939. They eventually moved to the United States in 1951. His wife died in 1986.

In news reports, Mr Imich said his good genes and a general healthy lifestyle contributed to his longevity.

Guinness is investigating the claim that 111-year-old Sakari Momoi, of Japan, is now the world's oldest man.

The world's oldest person is a woman, 116-year-old Misao Okawa, of Japan.