111-year-old US parapsychologist Alexander Imich crowned world's oldest

Imich's passion and curiosity about parapsychology shaped his motto, which is that one should "always pursue what one loves and is passionate about."

Robert Young, Senior Gerontology Consultant for Guinness World Records, verified the latest achievement by utilising Imich's birth record, immigration papers and university records.

Stuart Claxton, a Guinness World Records Official, visited Imich in his home in Manhattan's Upper West Side to present him with his official plaque.

Imich's history and recognition encompasses a variety of milestones, Guinness said.

"He is both the oldest living war veteran and the first 'oldest living man' to hold a doctorate," Young said.

Misao Okawa of Japan, who is aged 116, is currently recognised by Guinness as the world's 'Oldest Living Person' overall. She was born on March 5, 1898 and lives in Osaka.

The greatest fully authenticated age to which any human has ever lived is 122 years, 164 days by Jeanne Louise Calment of France, said Guinness.