How much is a British gold medal worth? £2m

Home athletes on the podium will earn riches beyond their wildest dreams from sponsors, TV shows and a host of other deals

As 2012 beckons, the dense fog of economic gloom shows no signs of lifting, so there's fat chance of a happy and prosperous New Year for most citizens of Great Britain. Though not for all. Those with winners' medals draped around their necks at the London Olympics will not only be enveloped by great happiness, but assured of considerable prosperity.

More than ever before, these Games will enrich victorious British competitors beyond their wildest imagination. Not from actual prize money, of course. But when they step up to that rostrum they will be standing on a gold mine of sponsorships and endorsements, TV adverts and shows, speaking engagements and newspaper columns.

Sir Chris Hoy, Victoria Pendleton, Jessica Ennis, Rebecca Adlington, Ben Ainslie, Mark Cavendish, Mo Farah, Tom Daley, Phillips Idowu, Keri-Anne Payne and Dai Greene are leading contenders for the gold standard. And to borrow a phrase from Del Boy, this time next year they could all be millionaires – if some aren't already.

Hoy's pedal power is believed already to have earned at least a couple of million after his three golds in Beijing which made him the biggest name in cycling. Before 2008 he was earning just £24,000 a year from Lottery grants and small sponsorships. Beijing brought him lucrative deals from Kellogg's, Harrods, Highland Spring, adidas and ScottishPower Renewables.

Swimmer Adlington, who said after Bejing that all she wanted was to buy a pair of Christian Louboutin shoes, could follow in the footsteps of Imelda Marcos should she strike double gold again.

Leading sponsorship agency Octagon, whose clients include the marathon runner Paula Radcliffe, estimate some British winners could pick up £2m before Rio 2016. Their vice-president Clifford Bloxham says: "Seven or eight Team GB athletes will be able to command big endorsements after 2012, earning sums on a par with top British stars like Andy Murray and Jenson Button."

No one is suggesting that medal-winners in team events or less popular sports will be millionaires overnight but many will still get nice little earners should they do well. Even practitioners of hockey, taekwondo, canoeing and handball now have managers, PR minders and agents.

But here's a prediction. There is one young man, as yet relatively unknown, who with a little luck – or a lucky punch – can be literally the biggest hit of 2012 and subsequently the highest earner. The aforementioned sums will be chicken feed to what 22-year-old Anthony Joshua will be worth – £5m is the estimate of one promoter – should he become the Olympic super-heavyweight boxing champion. It remains the richest prize in Olympic sport. Ask Audley Harrison: he made a million back in 2000 when he turned pro, without landing a blow. The seven-figure windfall, from licence payers' money courtesy of the BBC, was paid up front, together with another million from a sponsor. It turned out to be money for old rope and, as we know, it all ended in jeers.

Amir Khan also collected a cool couple of million in his initial three-year deal with Frank Warren – and that was only after winning silver at lightweight at Athens 2004. And James DeGale got an instant investment of around £1.5m from the same promoter after his acquisition of the middleweight title at Beijing 2008.

In boxing it is always the big boys who make the big money and, in the Olympic ring, they don't come any bigger than 6ft 6in Joshua, the London-born son of Nigerian parents who has the profile, personality and punch, together with a newly-acquired world amateur silver medal from Baku, where he lost on a hotly-disputed decision to the local Azerbaijani, having beaten the reigning Olympic champion Roberto Cammarelle.

Joshua says: "I'm made for the Olympic final. I'm not overwhelmed by the prospect. This is what I am supposed to do. I've not won it yet but I'm heading in the right direction."

His confidence is shared by Rob McCracken, Team GB's boxing chief. "We always knew Anthony was something special but his rate of progress this year, for someone still inexperienced, has been absolutely fantastic. He has every chance of being a star in his hometown Olympics."

Joshua has more heart than Harrison and a better chin than David Haye. When he won the ABA title two years ago he spurned an offer of £50,000 to turn pro, and there was 10 times that incentive on offer after his world silver. But he knows winning gold will make him worth a king's ransom. Or even a Don King's ransom.

Of course the boxing ring is strewn with shattered dreams of wannabes, and that Olympic title is by no means a foregone conclusion, even less the world heavyweight title which understandably is his aspiration.

But of all the potential 2012 achievers hoping to milk London's Olympic cash cow, Joshua seems the one most likely to be worth his weight in gold.