Coach Biranchi Das was taken into custody after Budhia's mother lodged a complaint with police in the eastern Indian city of Bhubhneswar.

Budhia told television channels that Das punished him by keeping him confined in a room without food for two days.

"He (Das) also beat me with a hot iron rod," Budhia said, showing burn marks on his hands.

The coach, who last year demanded 2,000 dollars a month from the state government for Budhia's upkeep, denied the charges and claimed he was being framed by the child's mother.

The slum boy, touted as the world's youngest long-distance runner, hit international headlines in May last year after he ran 65 kilometres (40.3 miles) in seven hours, collapsing just before the finish line.

The Orissa state child welfare department banned the boy, dubbed 'Forrest Gump' by the media, from distance running following medical reports that he was "undernourished, anaemic and under cardiological stress".

But Das, who is not a qualified coach, had maintained the boy's health was "normal".

"He's an asset to the nation," said Das. "It's a pity that he's surrounded by controversy. India has no marathon runners and when a kid starts running instead of supporting him the government is finishing his career."

Budhia was born in the slums of Bhubaneswar, the capital of Orissa state. His father was a beggar while his mother earns a living by washing dishes.

When his father died, Budhia's mother, unable to feed her four children, sold him to a ribbon vendor for 800 rupees (17 dollars).

Das said he paid the same money to "adopt" Budhia Singh and later trained him as a marathon runner.

"He came to me when he was three years. One day as a punishment, I told him to run and I forgot about it. When I met him after six hours he was still running," Das said.