By Stephen Gibbs
BBC News, Havana
Benito Martinez says he came to Cuba from Haiti in 1925
Cuba says the oldest man in the world is living on the Caribbean island.
Benito Martinez says he is 123 years old, while Cuban experts believe he is just four years younger than that.
If that is proved, he will comfortably break the world record. The current record holder is 113 and lives on the Caribbean island of Puerto Rico.
The Cuban says he was born in Haiti in the 19th century. He says his long life is down to no cigars or alcohol - but good food and a fair share of women.
Mr Martinez says he came to Cuba in 1925 to work on a sugar plantation on the island.
If he is anything near as old as the experts believe, he appears in extremely good shape - he is able to walk on his own and crack jokes.
He was presented to the world by the Cuban government at the inaugural meeting of what it calls the '120 Club'.
Its membership is mainly made up of people who are already more than 100 and want to live to a seriously ripe old age.
Cuba says that with its free healthcare, it is the best place in the world for men and women to grow old.
The idea for the club is believed to have come from none other than the Cuban President, Fidel Castro.
At a mere 78 he has not yet joined, but he might do one day.
Mr Castro's personal physician recently said that he saw no reason why the president should not live to be 125.