Investigators say the saga of a boy mistakenly thought to be floating high above Colorado in a homemade balloon was an elaborate hoax, with the intent of landing the family a reality television series.

Larimer County Sheriff Jim Alderden told reporters the alleged hoax had been planned for at least two weeks and that investigators suspect more people and an unnamed "media outlet" were in on it.

On Thursday, six-year-old Falcon Heene's parents called 911, claiming the boy was in the UFO-shaped balloon when it drifted away from the family's backyard.

When the balloon landed after an 80-kilometre flight, Falcon was nowhere to be found. He was discovered five hours later at home, hiding in the rafters of the family's garage.

Alderden said police believe they have enough evidence to file charges against the boy's parents Richard and Mayumi Heene. Authorities are also looking into a media outlet in their investigation.

"We do understand, looking at some of the documents already, that at least one of the media outlets has agreed to pay them some money with regards to this particular incident," Alderden said.

He would not name the outlet, but said he was not talking about a news organization and said it was a show that blurs "the line between entertainment and news."

Authorities were not clear if the deal was signed before or after the hoax, or if the media outlet was in on the fake story.

He told reporters that police will recommend that the following charges be filed against the Heene parents: conspiracy, contributing to the delinquency of a minor, false reporting to authorities and attempting to influence a public servant. Since the charges have not yet been filed, no one has yet been arrested.

Some of the charges carry a sentence of up to six years in prison and a $500,000 fine.

"Needless to say they put on a very good show for us, and we bought it," Alderden said, alleging Falcon may not have been hiding at all.

"For all we know he may have been two blocks down the road playing on the swing in the city park," he said.

Richard Heene said he's "seeking counsel," though it was unclear whether he was talking about hiring an attorney.

"This thing has become so convoluted," Heene told The Associated Press as tears welled up in his eyes. In a news conference, Alderden said Richard Heene showed "no evidence of remorse" for the saga.

While all three of the couple's sons knew of the hoax, none will face charges due to their ages, Alderden said. The oldest child is 10.

Authorities have also contacted local child protective services, but the children are still living with their parents for now, Alderden said.

'Balloon boy' captures world's attention

Millions of eyes were glued to TV sets on Thursday, watching the search for the young boy. Soon after the balloon left the family's backyard, Mayumi Heene told an emergency dispatcher that her son was in "a flying saucer," seemingly under the impression that Falcon had climbed into the balloon.

But media and members of the public grew skeptical of the family's story, particularly after it was revealed they had appeared on the reality show "Wife Swap," and that Richard, who is a storm chaser, had tried to pitch reality TV shows to a number of producers. Alderden said the couple met in acting school in Hollywood.

While police initially believed the story, their suspicions were raised after the family gave an interview with CNN, during which Falcon told his father "you said we did this for a show," when he was asked why he didn't emerge from his hiding place earlier.

"If you look at the nonverbal responses, as well as some of the verbal cues, not only for him but from the family, the children, their reaction, it became very clear to us at that point that they were lying," Alderden said.

In two other TV interviews that same day, Falcon vomited when asked again why he hid.

Investigators questioned both Richard and Mayumi at the local police station on Saturday night, and it was from those interviews that police gleaned enough information to obtain search warrants for the couple's home.

During the search, conducted late Saturday evening, authorities seized computers, telephone records and financial records. They were also looking for media recordings and any contracts related to a reality television show or a plan for such a show, Alderden said.

Should the district attorney choose to charge the couple, law enforcement agencies who participated in the pursuit of the balloon and the search for Falcon will likely seek restitution.

"If this is presented to the DA, if he accepts the charges and if it proceeds to court, we certainly will be seeking restitution, but unfortunately I don't have those figures," Alderden said. "Getting a dollar amount and the man hours has really been the least of our concerns at this point. We will be working on that throughout the week."

Alderden said local authorities will also meet with officials from the Federal Aviation Administration and the FBI, to determine if the couple will face any federal charges.

Military helicopters, and a ground rescue team were dispatched for the search for Falcon, and officials rerouted planes out of the balloon's airspace, delaying flights at Denver International Airport.

Using measurements of the balloon given by Richard Heene on Thursday, a Colorado State University physics professor, told police that it was possible for the balloon to lift Falcon, who weights 17 kilograms.

But once the balloon landed and police took proper measurements, the professor said it would have been impossible for the device, which was made of tarp, aluminum foil and a thin piece of plywood to fly away with the boy inside.

With files from The Associated Press