Balloon boy mother 'admits hoax'

The mother of the six-year-old US boy once feared missing inside a runaway helium balloon admitted the whole saga was a hoax, according to court documents.

Mayumi Heene told sheriff's deputies that she and her husband Richard "knew all along that Falcon was hiding in the residence" in Fort Collins, according to an affidavit that was used to get a search warrant for the home.

She allegedly told Denver investigators the incident was a hoax meant to make the family more marketable to the media.

"Mayumi described that she and Richard Heene devised this hoax approximately two weeks earlier. ... She and Richard had instructed their three children to lie to authorities as well as the media regarding this hoax," the affidavit said.

Richard Heene has denied a hoax. His lawyer, David Lane, said Friday he is waiting to see the evidence in the case.

"Allegations are cheap," Ms Lane said.

Mayumi Heene's lawyer, Lee Christian, was travelling and didn't immediately respond to messages left with his office.

Larimer County Sheriff Jim Alderden has said he will recommend charges against the Heenes including conspiracy, contributing to the delinquency of a minor, making a false report to authorities, and attempting to influence a public servant.

The most serious charges are felonies and carry a maximum sentence of six years in prison.

Mr Alderden said authorities also would be seeking restitution for the costs of the balloon chase, though he didn't provide a figure.

His office has said it will likely be next week before it forwards its findings to prosecutors to decide on charges.

In frantic calls to a TV station, the police emergency dispatcher and federal aviation officials, the Heenes reported that they feared Falcon was in the homemade, saucer-like balloon when it was accidentally launched from their back yard last week.

Millions watched on TV as media and National Guard helicopters tracked the balloon across the Colorado plains.

It landed in a dusty farm field, where ground crews looked inside but found no sign of the boy.

Later, the relieved-looking couple reported Falcon had been hiding in their garage the whole time. But suspicion heated up when Falcon made a comment on CNN that sounded like "You had said we did this for a show".

Sheriff's deputies questioned the parents separately on October 17, two days after the flight.

Mayumi Heene told authorities "she and Richard Heene had lied to authorities on October 15, 2009 (the day of the flight)," the affidavit said.

She told investigators "that the release of the flying saucer was intentional as a hoax. ... The motive for the fabricated story was to make the Heene family more marketable for future media interest," the affidavit said.

The Heenes twice had appeared on the television reality show Wife Swap, on which wives from two very different families trade places for two weeks. Acquaintances said Richard Heene had plans for other possible shows.