Remains of British explorer Matthew Flinders, who helped map Australia, found at Euston's HS2 site

For a man whose lifetime of exploration placed Australia on the map, it was something of an irony that Captain Matthew Flinders’s final resting place remained lost for so long.

Now, archaeologists carrying out a mass excavation of graves to make way for the arrival of HS2 have finally found the remains of one of Britain’s most celebrated seafarers.

Captain Flinders is one of around 40,000 people buried at St James’s Gardens, London, where the terminus of the high-speed link between the capital and Birmingham is due to be built.

His voyages at the start of the 19th century helped to chart - and ultimately name - Australia, when he became the first man to circumnavigate the island as commander of HMS Investigator.

Imprisoned by the French on his return journey in 1804, the Lincolnshire-born Royal Navy officer created a map of the landmass he had just confirmed as a continent and advanced Australia as a name.

While he was not the first person to use the term, it was popularised by his work and the continent, formerly referred to as New Holland or Terra Australis, was renamed by the British Admiralty in 1824.

More than 100 geographical features of the country are now named after Captain Flinders, including a mountain range, an island and one of Melbourne’s main streets.

He returned to Britain in 1810 and died four years later, aged 40.

However, the headstone marking his grave at St James’s Gardens was removed in the 1840s as Euston station was being expanded, meaning his whereabouts became a mystery.

It gave rise to the myth that the captain had been interred below platform 15.

Last week, a coffin bearing a lead depositum plate was uncovered by archaeologists, upon which the inscription “Capt Matthew Flinders, RN” could be seen.

Helen Wass, head of heritage at HS2, said:  “Given the number of human remains at St James’s, we weren’t confident that we were going to find him.

“We were very lucky that Captain Flinders had a breastplate made of lead, meaning it would not have corroded.

“We’ll now be able to study his skeleton to see whether life at sea left its mark and what more we can learn about him.”

A statue of Captain Flinders and Trim, the cat said to have sailed the globe with him, was installed at Euston station in 2014 to mark the centenary of his death.

It is expected his remains will be reburied at a separate location yet to be determined.

The High Commissioner of Australia to the UK, George Brandis, told the Telegraph he hoped a suitable memorial could be created to mark the spot Captain Flinders will be interred.

He said: "The Australian government, the Flinders family, the relevant civic and ecclesiastical authorities will have a discussion about the reburial of those remains and the creation of a permanent memorial to him.

"I'd envisage they would be interred near to the location where they were discovered, with a suitable gravestone.

"I would make the case (Captain Flinders) is one of three great figures of the discovery of Australia by Europeans, along with Cook and Phillip.

"It does well, particularly at a time like this, for English people to be reminded what a central role they played in the development of other nations."

Gillian Dooley, Flinders University honorary senior researcher, said the explorer - the university's namesake - could now "be treated with the respect he deserves".

"Even in death, after his short and unsettled life, he hasn't been allowed to rest in peace in the English countryside, which is what he wished for. Let's hope this can now be achieved," Dr Dooley told the ABC.

One of Australia's most celebrated historical figures, one historian described him as "a real man of the enlightenment".

"He really believed in developing a dialogue and friendship with the Aboriginal people," Dave Hunt told the ABC.

"They meet a hostile tribe in the Illawarra who look like they're going to attack ... and Flinders diffuses the situation in only a way that Flinders could do," Mr Hunt said.

"He produces a pair of scissors and gives them all free haircuts."

The find comes fewer than three months into the recovery work at St James’s Gardens, where burials took place between 1788 and 1853.

Other notable figures laid to rest at the site include Bill ‘the Black Terror’ Richmond, a former slave from New York who was reputed to have taught Lord Byron to spar.

It is one of 60 archaeological sites along the HS2 route that are due to explored as part of the multi-billion pound project, a move that has prompted protests by environmental campaigners.

Construction of the HS2 station is due to begin in the area later this year.

The discovery of his remains comes on the eve of "Australia Day" a controversial national holiday which falls on the date of the arrival of the British First Fleet to Australia.

Many Australians view the Fleet and men like Flinders as harbingers of the decimation of ancient Aboriginal societies and cultures.

There is added controversy over the role of an aboriginal Australian aide to Flinders named Bungaree, who has been largely eclipsed by his British captain, but who historians now believe played a crucial role in success of the voyages.

"To me Bungaree is one of those key iconic figures in the early history of Australia, but that hardly anyone knows about him, to me, tells a bigger picture of this country," John Paul Janke, co-chair of the National NAIDOC committee, told the ABC.

"I always feel as though we've been, as Australians, robbed of the true history of this country. And Bungaree is one of those classic examples.