The story barely reported by Indian media

It is a potential scandal that claims to strike at a key pillar of Indian democracy - the freedom of the press - yet it is barely being reported in the Indian media.

There's a simple reason for that: this alleged scandal involves many of the most powerful media institutions in the country.

A sting operation by a news organisation called Cobrapost claims to have revealed a deeply engrained bias towards the ruling Bharatiya Janata Party (BJP) within many of India's leading media groups, as well as a willingness among some of the country's most senior media executives and journalists to take money in return for pushing a political agenda.

Cobrapost, a small but controversial outlet known for undercover stings, describes itself as a non-profit news organisation that believes too much journalism in India has been "trivialised". It has dubbed its story "Operation 136" - the figure is a reference to India's ranking in the 2017 World Press Freedom Index.

Their website says its recordings show that some of the country's leading news organisations are willing to "not only cause communal disharmony among citizens, but also tilt the electoral outcome in favour of a particular party"- and all in return for cash.

Undercover stings of this kind are notoriously unreliable. The footage can easily be taken out of context or edited to change the meaning of a conversation or misrepresent its real nature.

An undercover reporter from Cobrapost, Pushp Sharma, says he approached more than 25 of India's leading media organisations, offering them all a similar deal.

He claimed to represent a wealthy ashram - a Hindu monastery - which, he said, was willing to pay large amounts of money in the run up to next year's general election in an attempt to ensure the BJP, a Hindu nationalist party, remains in power.

Mr Sharma says he outlined a three-stage strategy his paymasters wanted to bankroll.

First, he proposed the media organisations promote what he describes as "soft Hindutva" - the idea that Hindu faith and values are the defining ideology of India. He suggested this could involve promoting the sayings of Lord Krishna or retelling stories from the Bhagvad Gita, the epic poem that is one of the most holy texts of Hinduism.

The next stage would involve attacks on the BJP's political rivals, particularly Rahul Gandhi, the leader of the main opposition Congress Party.

Finally, the plan was to move on to promoting incendiary speeches from some of hard-line proponents of Hindutva, including some divisive radical Hindu figures.

The idea of this stage of the operation, Mr Sharma explained to some of the executives, was to polarise voters in the hope that the BJP would benefit at the ballot box.

Amongst the media groups Cobrapost says it approached were giants like Bennett Coleman, the media empire that owns The Times of India - the largest selling English language newspaper not just in India, but in the world.

It also targeted the The New Indian Express, another large English language newspaper, and the India Today Group, which owns one of the country's most popular television news channels.

Hindi language newspapers and regional media groups were also approached.

According to Cobrapost, all but two of the more than two dozen groups it had meetings with said they were willing to consider the plan.

Videos of the encounters posted on the Cobrapost website show media executives, editors and journalists discussing how they might be able to accommodate his proposals.

The different organisations come up with a whole range of suggestions, from publishing undeclared "advertorials", to paid news items and special features.

Some say they would set up "special teams" to push the ashram's agenda. There is talk of creating viral videos, jingles, quizzes and events.

Cobrapost has made some potentially very serious allegations about some of the countries most powerful media organisations.

In most democracies, claims like this would have generated a huge national scandal with banner headlines and public outrage.

But, here in India, only few online media organisations - including the Wire, Scroll and The Print - have given the story extensive coverage.

Some of the big media groups targeted in the sting have responded to Cobrapost's claims, however.

They deny any wrongdoing and say that the undercover footage has been edited to misrepresent the real nature of the encounters.

The Times of India, for example, says it is "a case of doctoring of content and falsification" and says none of the media organisations Cobrapost names "agreed to any illegal or immoral activity and no contracts were signed".

The Cobrapost videos appear to show Vineet Jain, the managing director of Bennett Coleman, the publisher of the Times of India, haggling over how much the group would need in order to consider the proposal. Mr Jain says he wants $150mn (£112mn) but finally settles for half that.

There is also a discussion about how any payment could be made in cash, possibly to avoid paying tax.

Bennett Coleman has since rejected any suggestion of dishonesty. In fact, an article in the Times of India explained that Cobrapost was the victim of what the newspaper calls a "reverse sting".

It says "senior functionaries" of Bennett Coleman were well aware that Mr Sharma was an imposter and deliberately went along with his proposals in an attempt to "trap the fraudster and discover his true intent".

The India Today group also denied that it had done anything wrong. In a statement it said that the company's managers would not do anything unethical, and that any advertising that divides the country on religious or caste lines will not be acceptable or aired on its channels.

Meanwhile the New Indian Express has said that there are no editorial issues for the newspaper because the meetings were between the undercover reporter and advertising executives and the discussion was only about the possibility of an advertising campaign.

It also said it would never accept advertisements which encouraged communal disharmony and that the executives made clear that any advertisement would need to be legally vetted.

There is no question that the Cobrapost allegations need to be treated with healthy scepticism. But there is also no question that they raise potentially troubling doubts over the independence of the media in India, particularly when it is a year away from a general election.

That the world's largest democracy languishes towards the bottom of the rankings for press freedom is already a matter of national shame.

If proven, these allegations would no doubt see India slipping yet further down the table.

A headline in the online news site Scroll captures the challenge the country faces.

"Cobrapost expose shows Indian media is sinking", it runs. "Now we can fight back or be drowned."