On a sunny Sydney afternoon, things look good from Sanjeev Gupta’s office on the 28th floor. From one window you can see the $35m waterside mansion he bought last week as an Australian bolthole for his family; from the other, the south end of the Harbour Bridge looms large.

But 1,500km west of Gupta’s blindingly white office suite, at the Whyalla steel mill in South Australia, things are decidedly grittier.

The mill, which was among assets the British billionaire bought from failed company Arrium in 2017 for about $750m, is losing money and even Gupta says it will require several years and hundreds of millions of dollars more before it turns a profit.

“It’s sub-scale and old technology … a tough steel market – these are all the ingredients for a problem,” he says.

Gupta has been feeling pressure over the way he has financed Whyalla and other businesses in an empire that employs about 45,000 people, including almost 7,000 in Australia, leading him to promise earlier this month to issue a consolidated set of numbers covering the whole enterprise.

Whyalla sits at one end of a complex financial chain that stretches to Bundaberg in Queensland, back to Gupta’s home base of London and off to Switzerland.

Throw in Gupta’s fight with Korea over allegations it is hurting Whyalla by dumping steel in Australia, questions about the level of government support his businesses need and a legal stoush involving former champion motorbike rider Mick Doohan and a $30m private jet, and he seems to have plenty on his plate.

Some questions he clearly wishes would stop being asked.

“Journalists are annoying everywhere in the world, you’re not unique,” he jokes.

Sanjeev Gupta with South Australian Liberal leader Steven Marshall during a symbolic march with supporters down the main street of Whyalla in September 2017. Photograph: David Mariuz/AAP

But he’s happy to talk about the troubles at the Whyalla mill.

When he bought it, a little over two years ago, he was painted as the town’s saviour. There was even a parade down the main street.

Hundreds of workers at the mill agreed to take a pay cut to keep it going, and the South Australian government said it would give a $50m grant to whoever bought the ageing facility.

As part of the deal, Gupta also got a business that recycles steel into building materials, which has been profitable even if it has also had some financial issues.

Whyalla itself, Gupta says, has “fundamental problems”.

OneSteel Manufacturing, the Gupta company which owns and operates the steel mill, lost $195m in the 2018 financial year, according to the most recent set of publicly available accounts, on top of a $120m loss the previous year.

“It certainly clearly was in trouble when I first came to look at it,” Gupta says.

News Corp is one notch away from junk. This word junk is just financial terminology

“In fact the very first discussions I had, they were very unfortunate, they were really about the fact that, OK, if it is going to die, how long is it going to take and what do you do with a town that has no other business?

“I have invested hundreds of millions of dollars trying to change that. I don’t think it’s an easy answer … there is no thinking that you can wave a magic wand and you have a solution.”

His plans to upgrade the plant include a solar farm under construction in a joint venture with the former Rudd government adviser Ross Garnaut that Gupta says will be “Australia’s biggest”. He also wants to turn the mines that provide the mill its iron ore into pumped hydro power plants once they are tapped out.

“These things don’t get built in one day, it takes time for steel plants to be built or reformed,” he says.

‘Junk is just financial terminology’

All this money has to come from somewhere, and so far much of Gupta’s backing has come from Greensill Capital, a London-based finance house founded by a Bundaberg sugar cane and sweet potato farmer Lex Greensill, which has had its own share of controversies.

Gupta says Greensill continues to finance the Whyalla mill and, until recently, also backed the steel recycling business Liberty Infrabuild.

Greensill, which declined to comment on its relationship with Gupta, specialises in a form of lending known as “supply chain finance”, where it agrees to pay the suppliers of a business early in return for a cut of the invoices.

Greensill has been embroiled in some controversy about loans it had bundled up and sold to investors in funds run by a Swiss group called Global Asset Management, but Gupta brushes aside any suggestion of implications for his companies.

“It’s not our business really,” Gupta says. “There’s nothing wrong in it, it’s perfectly good paper, it’s a perfectly good asset.”

Meanwhile, Gupta’s plans to list Liberty Infrabuild have been put on ice.

He had recruited a board including the steel industry veteran Ray Horsburgh and cleaned up the company structure in preparation for an IPO this year.

“He’s doing well in getting the business to turn around and we felt, and I think the advisers felt, that he needed more mileage than one year’s results,” Horsburgh says.

“It was stuffed and it’s starting to make money.”

Until the middle of last month, Liberty Infrabuild also faced a potential debt crisis – one that Gupta had to reach into his own pockets to solve.

On top of its financing from Greensill and another similar group, White Oak, it had borrowed $230m from the banks – and this needed to be paid back by February next year.

Sanjeev Gupta, photographed in his Sydney office in Aurora Place. Photograph: Jessica Hromas/The Guardian

Gupta initially proposed to fill the gap by borrowing US$475m in the form of high-interest bonds, but was forced to reduce this to US$375m and stump up an additional uS$150m of his own money to get the deal away.

He says the money has been used to fix the company’s finances, including by buying out Greensill, and it no longer needs to worry about the February deadline.

The ratings agency Moody’s slapped a Ba3 rating on the bonds, citing risks including “the concentrated ownership of the company”, which could result in “cash flow leakage to boost returns or support other businesses within GFG”.

Ba3 is what is politely called “below investment grade” or in the usual jargon of the market “junk” – but the J-word sets Gupta off like a firecracker.

“FMG is junk,” he says, referring to bonds issued by the Fortescue Metals group controlled by Australian mining magnate Andrew Forrest.

“News Corp is one notch away from junk. This word junk is just financial terminology. Most of the universe you know of in this country in terms of heavy industry is going to be in that category.

“I think we’re better than that, but it’s the first rating we’ve got so I’m OK with that.”

‘My path is very clear’

Gupta may have made nice with the capital markets, but he doesn’t shy away from a fight.

He has asked the Australian anti-dumping commission to investigate Japanese, Korean, Taiwanese and Thai steel mills he accuses of hurting Whyalla’s profitability by offloading products in Australia at below what it costs them to produce.

If I go to the toilet, it will probably be in the press next time. Sanjeev Gupta

In a response filed with the commission last month, Korean steelmaker Hyundai sledged Gupta’s companies for have an “opaque company structure” and accused him of selling steel from one company in his group to another at a loss before selling it to customers at a profit.

Gupta bristles.

“It’s nuts,” he says. “It’s none of their business almost … A foreign steel producer, what right do they even have to think about what we are doing here.”

It’s also irrelevant, he says.

“The dumping rules are about what price are they selling at here, versus what are they selling at in Korea.”

He also rejects notions he has asked for government handouts, saying that the $50m offered by South Australia – which the government says is yet to be handed over – was on offer to any successful bidder for Whyalla.

This week, the Sydney Morning Herald reported he had asked the NSW state government for tax breaks on facilities in western Sydney.

“The concept of governments generally, not this government in particular but any government, taxing something which is losing money or is bankrupt or has gone into trouble is crazy,” Gupta says.

Gupta has also found time to fight a jet sales company, Jetcraft, over a private plane he was going to buy in a deal brokered by Mick Doohan.

In legal proceedings in the UK and the US, Gupta alleged Jetcraft inflated the price by interposing a company between him and the actual seller.

But in June the high court of England and Wales ruled he had forfeited his US$2.5m deposit, and last month Gupta settled.

“If I go to the toilet, it will probably be in the press next time,” Gupta says when Guardian Australia raises the case. “I tried to do an acquisition, there was an issue, it was settled, nothing happened.”

Gupta may not have bought the plane, but last week he did lay out a reported $35m to buy that mansion he can see from the window – Bomera, a colonial-era sandstone pile in the exclusive Sydney suburb of Potts Point.

He says that after two years living here during the Arrium acquisition he loves the country – but he and his family are now based in London.

There’s something else Gupta wants to make clear: he doesn’t care for the haters.

“It doesn’t matter what schools of criticism or scepticism there is, there is no way I am going anywhere but where I exactly intended to,” he says. “I am not veering away from my path, my path is very clear in my mind.”