FORT COLLINS, Colorado (AP):

THE PARENTS who set off a worldwide drama by reporting their six-year-old son was inside a flying saucer-like helium balloon hurtling over Colorado concocted the stunt to market themselves for a television show, a sheriff said yesterday.

Larimer County Sheriff Jim Alderden said no charges had been filed yet and the parents were not under arrest. He said he expected to recommend charges of conspiracy, contributing to the delinquency of a minor, making a false report to authorities and attempting to influence a public servant.

Some of the most serious charges each carry a maximum sentence of six years in prison and a US$500,000 fine. The sheriff said if charges were filed, his office would seek restitution, but he did not know the total cost of the rescue effort, which included military helicopters, a ground rescue and even a mounted posse. Officials also re-routed planes around the balloon's flight path and briefly shut down some flights from Denver International Airport.

Elaborate scheme

Alderden said the parents, Richard and Mayumi Heene, "put on a very good show for us, and we bought it".

Alderden said at an extra-ordinarily candid news conference that the boy, Falcon Heene, may not have even been hiding in the rafters of the family's garage during the intense five-hour search for him Thursday afternoon.

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

Richard and Mayumi Heene were shopping at a Wal-Mart with their three sons as Alderden told reporters at the sheriff's station that the whole thing was a hoax.

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.

He said his wife was holding together better than he was.

The sheriff said all three of the Heenes' sons knew of the Thursday hoax, but likely won't face charges because of their ages. The eldest son is 10. One of the boys told investigators he saw his brother get in the balloon's box before it launched.

No remorse for deed

Heene, a storm chaser and inventor, and his family has appeared on the ABC television reality show 'Wife Swap'. Alderden said the couple met in acting school in Hollywood. Richard Heene has described himself as an amateur scientist, but Alderden said Heene has only a high-school education.

"He may be nutty, but he's not a professor," Alderden said, adding Heene showed "no evidence of remorse" for the episode.

Alderden said interviews with the parents Saturday resulted in enough information to get a warrant to search the house. He said they were looking for computers, emails, phone records and financial records.

Alderden said the children were still with the parents yesterday morning, and child-protective services had been contacted to investigate the children's well-being.

Alderden said the "aha moment" came when, during a Thursday night interview with CNN, Falcon turned to his dad and said what sounded like "you said we did this for a show" when asked why he didn't come out of his hiding place.

"If you look at the non-verbal 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.

Last Friday, Falcon got sick during two separate TV interviews when asked again why he hid.