The balloon is believed to have broken free from the boy's family home
A sheriff in the US state of Colorado says the parents of a boy mistakenly believed to have been carried away by a helium balloon will face charges.
Sheriff Jim Alderden was speaking after interviewing the parents of Falcon Heene, aged six, for a second time.
The boy was feared to have been in a weather balloon which flew away on Thursday, but was later found at home.
Sheriff Alderden had earlier said that he did not think Richard and Mayumi Heene were behind a deliberate hoax.
He has not specified what charges will be brought, but the couple have not been arrested.
"We were looking at Class 3 misdemeanour, which hardly seems serious enough given the circumstances," Sheriff Alderden said.
A search warrant is being obtained for the couple's home in Fort Collins, and Sheriff Alderden raised the possibility of federal charges, saying that he was talking to the Federal Aviation Administration
The Heenes are expected to give a press conference later.
The disappearance of Falcon Heene became a media drama that gripped the nation.
Suspicions were aroused when the child, when asked on TV why he had stayed hidden, said "we did this for a show".
Father Richard, wife Mayumi, three sons - Brad, Ryo, Falcon
Family appeared on reality TV show Wife Swap, described as science-obsessed
Father is an amateur scientist and keen "storm chaser"
Home videos posted on YouTube, including three sons performing rap song
The boy, his two brothers and his parents gave numerous TV interviews late on Thursday and early Friday.
His father, Richard Heene, insisted that his son's disappearance was not staged.
He and his wife Mayumi have previously appeared on the reality TV show Wife Swap, leading to speculation in the media that the latest incident might have been a publicity stunt.
US news networks devoted hours of live coverage to the drama on Thursday after it was reported the boy might be in a balloon floating high over Colorado.
When the aircraft landed in fields there was no trace of him, prompting a major ground search and further fears for his safety.
Officials said Falcon Heene may have hidden because he was scared
It was finally announced that the boy had been found alive and well in the roof-space of the garage at his family's home.
In spite of quick denials from his father, speculation that the Heenes had faked the entire incident persisted, when the family appeared on more US TV talk shows.
And in a bizarre twist, Falcon himself became physically ill while his father was asked direct questions on ABC and NBC about whether or not they had staged an elaborate hoax.
Mr Heene battled on while his son was being sick, telling his NBC interviewer there was "absolutely" no hoax.
He repeated the statement on Saturday, prior to being interviewed by the sheriff, telling reporters at his house there had been "absolutely no hoax".