NEW YORK ( CNN ) -- For more than a half-century Jerry and Marilyn Damman wondered what happened to their 2-year-old boy , who mysteriously vanished into thin air outside a Long Island bakery . Steven Damman and his sister disappeared from outside a bakery in 1955 . His sister was found safe . Now , 54 years later , a Michigan man claims he is the missing child whose name was Steven Damman . Within the last six months , the unidentified man contacted Nassau County , New York , police and said he had credible evidence that would link him to the case of the missing toddler , according to police Detective Lt. Kevin Smith . Nassau County police turned the case over to the FBI in Detroit . So far , authorities will not release the Michigan man 's identity and wo n't say why he believes he is Steven Damman . The FBI is conducting DNA testing , Smith said . Sandra Berchtold , spokeswoman for the FBI Detroit bureau , said only , `` The FBI investigates all leads in kidnapping cases , but can not confirm or deny the existence of an investigation in this matter . '' In 1955 , Marilyn Damman took her toddler , Steven , and his baby sister , Pamela , to a bakery in East Meadow . The mother went inside to do some quick shopping , leaving her 2-year-old and baby girl in the stroller outside . But when Damman returned , her children were gone . A short time later , blocks away , the baby girl was found unharmed and the stroller was intact , but Steven was missing , Smith said . Thousands of searchers looked for the toddler , but the boy was nowhere to be found . Hitting one dead end after the next , the Dammans packed up and moved from New York back to Iowa , Jerry Damman said . And until now , they thought there was little chance of ever seeing their son again . Jerry Damman , who lives on a farm in Iowa , told CNN , `` You never give up hope , [ but ] things dim after all those years . '' He said he is n't ready to comment on the latest developments for various reasons . Damman says authorities have contacted him , but he has not yet given DNA samples . A few years back , Steven Damman 's sister gave a DNA sample in connection with the 1957 Philadelphia case of a young boy 's body found in a box . In that case , all indications were it was not Steven Damman .
Unnamed young man says he was toddler who went missing in 1955 . Year - old William Damman vanished from in front of a Long Island , New York , house . Toddler 's father : ` ` You never give up hope , [ but ] things dim after all those years '' The FBI is conducting DNA testing , says Nassau County police officials .