OSAKA -- A 12-year-old runaway from Colorado who illegally entered Japan by pretending to have been separated from his mother has been returned to the United States, it was learned Wednesday.

The boy, who ran away from home after quarreling with his grandmother, had been under police custody in Seattle, more than 1,000 km away from Colorado. But the youngster eluded police and hopped onto an international flight at Sea-Tac International Airport on Sept. 1, bypassing proper boarding procedures by pretending to be the grandson of an elderly couple, according to police here.

When the plane arrived at Kansai International Airport on Sept. 2, he told an immigration official that he had strayed from his mother.

Sympathizing with the boy, the immigration official began to search for his mother without checking his passport. The boy, left unattended, then sneaked past, police said.

The boy was found soon afterward and put under police custody inside the airport. The next day, he was returned to the U.S. after his identity was confirmed by the U.S. Consulate General in Osaka.

"This is a case in which an immigration official forgot about the basics of examination procedure. We will do our utmost to prevent the occurrence of similar cases and we will also call on airlines to reinforce their checking procedures," an Osaka immigration official said. Ishihara and friends talk about Tokyo