Australian radio host Alan Jones was only halfway through his $8 million two-year contract a month ago, then he suddenly announced the end of his career.

Both Jones and his employer Nine cited "health reasons" but that version of the story misses some key details.

The Sunday Telegraph reports that, following the shock jock's comments about New Zealand Prime Minister Jacinda Ardern, advertisers quickly started backing away.

Last year, 2G quickly lost advertising after Jones called Prime Minister Jacinda Ardern "a complete clown".

Jones drew flak from all quarters after telling his listeners Australian Prime Minister Scott Morrison should "shove a sock down the throat" of Ardern.

Jones had taken umbrage after he thought Ardern had been critical of Australia's efforts to tackle climate change.

Jones later apologised to Ardern, saying he never intended to suggest any violence towards her when he said he wanted to "shove a sock down [her] throat".

It was one of many controversial episodes in a radio career marred by many polarising comments.

In an article in today's Sunday Telegraph, Annette Sharp tells the "inside story" of Jones' departure, with one media veteran saying "there is just no way he was going to leave of his own volition".

Nine Radio boss Tom Malone is said to have paid Jones a visit at his property a couple of weeks ago.

The official version is that Jones invited Malone for lunch along with Jones' agent Nick Fordham.

They said he had decided it was a good time to walk away, as he had a good relationship with the new Nine management team - unlike the previous leadership team, with whom he'd had a lot of trouble, as it moved to sack him in 2019.

"It was Alan who invited me down to his farm for lunch," Malone said, according to the Sunday Telegraph.

"We were able to facilitate Alan's request to stand down due to health reasons."

However, sources inside Nine Entertainment say it was, in fact, Nine who called the meeting.

It's been eight months since Jones made the controversial comments about Ardern, which led to advertisers walking away.

In fact, more than 100 advertisers have pulled their ads from the radio station, including Coles, Big W, Commonwealth Bank, Bunnings and McDonald's. That boycott cost them as much as $80,000 a day.

Ad executives say Jones' comment about the New Zealand Prime Minister have so far cost the company $20 million - about half of the radio station's annual ad revenue.

It has also had a great impact in Nine's ability to do business with premium advertisers across its multiple platforms.

It was the final nail in the coffin for the relationship between Nine and Jones, which had been damaged for some time.

Sources told the Sunday Telegraph Jones' retirement had been in the works for about three months.

While it is true he had some health issues, those with inside knowledge say that was not the cause of the retirement.

"Alan is in rude health at the moment. A man who is normally very busy, has been taking it easy, and if you listen to him on air, he's been in terrific form. Giving it to politicians left and right. He's been blowing doors off."

The same sources say he gave Malone some terms and conditions for his departure, including walking away on full salary and get paid out the balance of his $8 million contract.

He also told Nine he wanted his production team to either be paid out or offered new roles. Jones also wants his job to go to drive host Ben Fordham.

Another three are considering offers to remain at 2GB. Nine CEO Hugh Marks is confident the radio station that Nine fully acquired in August 2019 for $114 million will survive Jones's departure: " [Macquarie/Nine Radio] can survive the loss of any of its talent," he said in 2019. Jones will now concentrate on his commitments to Sky News following word he has been negotiating to increase his Sky workload from two nights a week, as per his current contract, to four.

Podcasting opportunities – as opposed to radio that might be in breach of his Nine contract – are believed to be on the table at Sky.

As Nine seeks to tie up loose ends concerning Ben Fordham's 2GB contract – presumably he's after a large pay bump – Nine is banking on Fordham for a revival of revenue fortunes. The new talent roster that bears little resemblance to the one set in place by the previous regime – with only Hadley in his former timeslot.