The British commoner who may carry down Norway’s monarchy: A sperm donor secret may threaten to derail the long run King – already embattled by his spouse’s Epstein connections and stepson’s rape trial

Under siege from the Jeffrey Epstein scandal and facing separate accusations of rape and other criminal offences, the Norwegian royal family faces new and even more alarming challenges ahead.

A forthcoming book will open up a 120-year-old can of worms, questioning whether the royals have any claim to the throne at all.

Princess Mette-Marit, wife of Crown Prince Haakon, was exposed when it was revealed she’d exchanged more than 100 emails with Jeffrey Epstein and had a secret four-day stay at his Florida mansion when he wasn’t present.

Damningly, Epstein later described the 52-year old blonde princess, whose husband will one day be king, as ‘twisted’.

Separately Mette-Marit’s son from a previous relationship, Marius Borg Hoiby, is on trial in the Norwegian capital Oslo this week facing 38 criminal counts, including four of rape.

Support for the royal family in this formerly staunch monarchist country has slumped from 70 per cent to 53 per cent, with one-third of the population now calling for a republic.

And all that is ahead of the publication later this year of a book investigating whether, in fact, the Norwegian royals have any right to sit on the throne at all.

The charge against them is that in 1902, Princess Maud of Wales – married to the future King – employed a sperm donor to produce a son and heir for the Norwegian throne.

That son, Prince Olav, was born in 1903 at Appleton House at Sandringham, and succeeded to the throne as King Olav V in 1957. He died in 1991 and his son King Harald, 88, now occupies the throne.

Photographs of Guy Francis Laking, a British ex-public schoolboy, published a few years ago, sent shockwaves through the Norwegian establishment – because when placed next to pictures of Crown Prince Olav at a similar age, the two men bore an eerie resemblance to each other.

One, an English commoner, was the father of the other, it was alleged.

If true it means that the present King of Norway has no right to call himself the monarch of his over six-million-strong kingdom.

Scandinavian historian Tor Bomann-Larssen unravelled the story. Guy Laking, he revealed, was the son of the royal physician, Sir Francis Laking, who attended our King Edward VII.

After nearly seven years of marriage Maud, Edward’s daughter, had failed to become pregnant and she was now approaching her 33rd birthday. To ensure Norway’s line of succession, a son and heir was required – pronto.

But, according to Bomann-Larssen, Maud’s husband King Haakon was infertile and unable to produce an heir.

So, it is alleged, Maud came to London, and in October 1902 underwent a pioneering sperm-donor treatment at the hands of Sir Francis Laking. The donor was his son Guy.

Nine months later Prince Olav was born, and as he grew into manhood the similarity between the two men – king and commoner – became increasingly evident. But it meant that Olav did not have his father’s blood.

In Norway, Bomann-Larrsen’s theory has been angrily questioned by pro-monarchy supporters. But the answer to the mystery may finally be settled by the publication later this year of a new biography of Queen Maud by historian Arnhild Skre.

Skre has travelled between Norway and Britain and elsewhere in her search for the truth. For the moment, her lips are sealed as to her findings.

But today the Daily Mail can reveal for the first time startling evidence which points directly towards Laking likely being the father of King Olav.

Two months after Queen Maud’s alleged artificial insemination, her brother, King George V, issued his first end-of-year Honours List.

Buried in the section devoted to the Royal Victorian Order – the award ‘for personal service to the sovereign’ – appeared the name of Guy Francis Laking. Everyone else receiving the coveted award that year had served the king on his recent eight-month tour of the British Empire on HMS Ophir, a P&O steam liner temporarily reclassified as the Royal Yacht.

There among the other recipients, and with no explanation as to why he’d qualified for this prestigious award, is Laking’s name.

At the time the doctor’s son was an armoury expert working for Christie’s, the auctioneers, with no special connection to Buckingham Palace. His elevation to this highly exclusive order raised eyebrows within the royal circle – because all the other recipients had close ties to the Crown, and were much older.

Given no explanation why someone who hadn’t served the Crown was receiving an intimate decoration from the sovereign himself, a possible conclusion to be drawn is that this was the King’s way of thanking Laking for his secret services to his sister Maud, and to the Norwegian crown.

It turned out to be only the start of a major reward for an act requiring very little effort.

Laking was a playboy and a spendthrift, and his earnings at Christie’s had done little to cover his expenditure. So King George created a post specially for him at Windsor Castle – as Keeper of the King’s Armoury. It brought Laking firmly into the royal compound from where he would become a recognised part of the machine of monarchy.

Once ensconced at Windsor, Laking acquired a status above his station – nobody knew why – and started to flex his muscles.

Soon he was touting the idea of a Museum of London, to be created under royal patronage – no ordinary museum, but one to be housed in the State Apartments of Kensington Palace. King George V and his family, including the future King George VI, obligingly came to the opening night – and from then on Laking was feted for his royal connections and grew rich on them, buying himself a large mansion in Regent’s Park.

Whether he ever met Queen Maud, the mother of his child, is not recorded.

Born the daughter of Edward VII and brought up in England, Maud was only willing to give herself up to the life of queen consort in a chilly foreign land on the understanding she’d spend two months a year at Appleton House, and mingle at the parties at Buckingham Palace. She did her duty in producing an heir to the throne of Norway, but had no further children. She died in London in 1938.

Guy Laking, the supposed commoner father of a king, was to die aged 44 from a heart attack. If now it’s finally confirmed he fathered King Olav, it will mean that both Haakon’s reign and that of his son Harald, the present king, are invalid.

And with a beleaguered Norwegian royal family already under incredible public pressure, some argue, it could well signal a swift end to the monarchy in that snowy land.