Mikelle Biggs, 11, was last seen with her younger sister waiting for an ice cream truck outside their home in Mesa, Arizona on January 2, 1999

A mysterious dollar bill has been uncovered that may provide clues on the disappearance of an 11-year-old girl who vanished more than 19 years ago.

Mikelle Biggs was last seen with her younger sister waiting for an ice cream truck outside their home in Mesa, Arizona on January 2, 1999.

The dollar bill, which has a cryptic message written on it, turned up last week in Wisconsin more than 1,400 miles away from where Mikelle went missing.

'My name is Mikel Biggs kidnapped From Mesa AZ I'm Alive,' the message reads.

The bill, which is from 2009, was handed over to police in Neenah on March 14.

While it appears to be written in child-like handwriting, Mikelle's first name is spelled wrong.

Neenah Police Investigator Adam Streubel told the Arizona Republic that they have been investigating the clue but fear it might not be legitimate and could be a cruel joke.

Streubel said it was proving impossible to trace how the note ended up in Neenah and how many people have come in contact with the bill.

The dollar bill from 2009 has a cryptic message written on it saying: 'My name is Mikel Biggs kidnapped From Mesa AZ I'm Alive'

Mikelle, pictured on left with her younger siblings, was last seen with her younger sister waiting for an ice cream truck outside their home in Mesa, Arizona on January 2, 1999

'There was a little spring of hope for a second, and then reality set in,' he said.

'There is nothing you can do with it, which is rather frustrating.'

Police said while they don't often get tips any more in relation to Mikelle's disappearance, they still investigate every one in the hope it breaks the cold case.

Mikelle's sister Kimber was the last to see her in 1999 when they were playing outside their home while waiting for the ice cream truck.

She vanished after being separated from Kimber for about 90 seconds.

Mikelle's bike was found on the street nearby, as well as the two quarters she was planning to use for her ice cream.

Authorities tracked down every ice cream truck in the state in the search for the little girl and interviewed more than 20 sex offenders.

