FORT COLLINS, Colo. - The man who orchestrated a hoax that his child had been carried away on a balloon, a story that riveted television news audiences, turned himself in Monday to begin a 90-day jail sentence.

Richard Heene pleaded guilty to attempting to influence a public servant after the Oct. 15 saga that captivated a national television audience.

But Heene now says he truly believed his 6-year-old son Falcon was inside the balloon and that he pleaded guilty only to appease authorities and save his wife from being deported to Japan.

Mayumi Heene confessed to deputies, authorities said, and she pleaded guilty to filing a false report. She faces 20 days in the Larimer County jail.

Richard Heene told The Associated Press last week that his wife misunderstood the meaning of the word "hoax" when she purportedly confessed.

"My wife's first language is Japanese, not English," Heene said. "My wife came home in tears wondering what she might have said. She opened this Japanese-to-English dictionary, and she walks up to me crying her head off, and she says to me, 'I thought hoax meant an exhibition."'

In other interviews last week, Heene said investigators presented inconsistencies to the media, and he denied calling a TV station before dialing police, as authorities said he did.

Authorities dismissed Heene's arguments.

District Attorney Larry Abrahamson said it was the Heenes and their attorneys, not prosecutors, who brought up the issue of deportation.

"We had been working with the attorneys for both he and his wife before charges were even filed," he said. "There was a lot of discussion about what was going to happen, about how and why. We were surprised that now he's coming out and saying that it wasn't a hoax."

Sheriff Jim Alderden said Mayumi Heene understands English better than her husband says she does.

"The interview was much more than, 'Mayumi, is this a hoax?' and she admitted to it. She went into the details of it," Alderden told the AP last week.

Mayumi Heene's statement to sheriff's investigators -- in which she detailed the couple's efforts to pitch a television show, their financial difficulties, and their actions in the weeks leading up to the event -- that make up the bulk of the case against the couple.

The Heenes must also pay restitution for the rescue effort that sent officers from two counties and other agencies scrambling. The Colorado National Guard launched two helicopters to track the balloon and possibly rescue the boy. Prosecutors estimate the Heenes owe $48,000, though Richard Heene's attorney could provide a different estimate by a Jan. 25 deadline.

The balloon's two-hour, 50-mile (80-kilometre) journey was followed on live television, as many feared the boy was in a compartment of the balloon. Authorities said Falcon Heene was hiding at home, in a box in the garage rafters, while the drama unfolded.

The silver balloon was owned by the boy's parents and tethered behind their home in Fort Collins, about an hour north of Denver. The Heenes are amateur storm chasers who are known to take their children along as they pursue bad weather, and the family has appeared twice on the TV reality show "Wife Swap."

Richard Heene also faces an $11,000 civil penalty from the Federal Aviation Administration. The balloon briefly shut down a runway at Denver International Airport.

He must serve 30 days before he can participate in the jail's work release program.