NEW DELHI (AFP) - The percentage of Indians living below the poverty line has fallen to 22 per cent from 37 per cent in just seven years, according to official data released on Tuesday, but the figures were dismissed by critics as "deeply flawed".

Calculating poverty is a hugely controversial topic in Asia's third-largest economy and the debate over the latest numbers could prove particularly heated as they come ahead of an election year in which the Congress government is seeking a third term.

The poverty rate fell by a robust 15 percentage points to 22 per cent in 2011-12 from 37 per cent in 2004-05, the figures from India's influential economic Planning Commission showed.

While economic growth slowed last year to a decade low of 5 per cent, the Congress government, in power since 2004, argues near double-digit expansion in previous years has driven a dramatic reduction in poverty in the country of 1.2 billion people.

The number of extremely poor people in absolute terms tumbled to 269.3 million in 2011-12 from 403.7 million in 2004-05, the commission said.

According to the commission, anyone with less than 33 rupees (60 Singapore cents) to spend a day in urban areas and less than 27 rupees a day in rural areas is counted as under the poverty line.

"These figures are deeply flawed and unrealistic about the actual conditions in the country," Mr Miloon Kothari, former UN Special Rapporteur on the right to adequate housing, told AFP.

"If you see the situation in the cities and villages it is quite clear there has not been such a huge reduction in poverty," Mr Kothari, now a leading Indian human rights activist, said.

According to the World Bank, nearly 70 per cent of India's population lives on less than US$2 a day - often cited as the baseline for poverty in the country.

India's poverty estimates are used to determine public access to welfare benefits such as subsidised food.

The figures will be used by India's states to start identifying beneficiaries for the populist government's flagship cheap food scheme that it sees as key to its hopes of re-election.

Congress party chief Sonia Gandhi has asked states to start rolling out next month the subsidised food programme, which will be the world's largest, offering grains at a fraction of market prices.

"State governments can use the updated data for identifying beneficiaries," Food Minister K.V. Thomas said, though the food security scheme will reach far more than the 269.3 million people identified as below the poverty line.

It will offer grains to nearly 70 per cent of the population, or 820 million people.