U.S. officials took possession Wednesday of an MP3 player that a New Zealand man found held 60 U.S. military files, including names and telephone numbers of American soldiers, the man said.

Chris Ogle, 29, from the northern city of Whangarei, said he bought the music player in February or March last year for $18 dollars at a thrift shop in Oklahoma City and that he found the files when he linked the device to his computer.

"I was very surprised," he told The Associated Press.

"I was curious enough to keep looking and I guess the more I looked the more intense it seemed to me," Ogle said. "Each time I looked at it I became more convinced ... it was possibly something bigger."

The private information in the files included troops' U.S. Social Security numbers and even which female troops were pregnant.

Details of equipment deployed to bases in Afghanistan, including the main U.S. base of Bagram, and a mission briefing were also found in files, most of them dated 2005. Some of the files included a warning that the release of the contents was "prohibited by federal law."

Ogle, who lived and worked in Oklahoma for five years until last month, said he had no idea about the origins of the device, and that it "didn't really ever work" as an audio player, with the sound cutting out before "it made it even through an entire track."

Two U.S. Embassy staff from the capital, Wellington, visited Ogle at his home Wednesday and took possession of the MP3 player, exchanging it for a new one.

"That was cool. It was a pretty serious upgrade," Ogle said, laughing.

Ogle said the men showed him U.S. Embassy identification and asked him if he had made any copies of the files.

"I said 'yes, one, and you're welcome to it,"' Ogle said.

"People around me were suggesting I should get something from this and it even came up in conversation but at the end of the day I had promised to give it to them and I did," he said.

The pair left with the music player and a computer disk with the only copy of the 60 files.

Embassy spokeswoman Janine Burns said the player "will now be sent back to Washington where they will take steps to see what's on it."

Burns was unable to say whether officials would try to trace the previous owner of the player or the origin of the sensitive military files.

"We understand the MP3 player he bought in Oklahoma didn't play music so we hope he will have more luck with this (new) one," she added.

It's not the first time such data files have surfaced in public.

In 2006, shopkeepers outside the Bagram base said they were selling flash drives with U.S. military information that had been stolen by some of the 2,000 Afghans employed as cleaners, office staff and laborers at Bagram.

Included on some memory drives seen by AP at the time were the Social Security numbers of hundreds of soldiers, including four generals, and lists of troops who had completed nuclear, chemical and biological warfare training.