Balloon chase

The balloon flew for more than 80km before landing in a Colorado field [Reuters]
Cathy Davis, a Larimer County sheriff's department spokeswoman, said earlier that the boy and his brother were playing outside when the older boy saw the younger one go into a compartment at the bottom of the balloon before it broke loose from its tether.

But Alderman later said that Falcon had been inside the garage while the balloon was chased by the local authorities and the media throughout the course of its two-hour, 80km, flight.

The balloon was capable of flying to an altitude of about 3,000 metres, a height where oxygen is in short supply.

Helicopters followed the silver balloon, which was reportedly made by the boy's father.

The balloon's basket was enclosed, making it difficult to ascertain whether anyone was trapped inside.