Drinks giant Diageo is to construct a new whisky visitor centre in Edinburgh as part of a £150m investment.

The Johnnie Walker visitor experience aims to bring to life "the story of the world's most popular Scotch whisky" and welcome millions of visitors each year.

Diageo will also upgrade facilities in its existing network of 12 distilleries in order to boost whisky tourism.

The firm said the £150m plan, which will be implemented over three years, is Scotland's biggest single investment in whisky tourism.

As well as the new centre in Edinburgh, four distilleries which produce Johnnie Walker will form part of a Scotland-wide tour based on the drink.

Glenkinchie, Cardhu, Caol Ila and Clynelish distilleries represent four regional flavour variations of whisky, Lowland, Speyside, Island and Highland respectively.

Diageo said the plans will provide fresh opportunities for unemployed young people to learn new skills.

Sites around the centre of Edinburgh are being assessed for the new facility.

Politicians have welcomed the investment, with First Minister Nicola Sturgeon saying: "This significant investment will not only help attract more tourists to Scotland, offering world class visitor experiences, but it also underlines the fundamental importance of the whisky sector to Scotland's economy.

"Last week, I launched Scotland is Now, a new campaign that will put Scotland in the international spotlight and showcase the country's world-leading assets, such as whisky, to a global audience.

"Today's announcement highlights to the world that Scotland is a leading destination for tourists and business investors."

Scottish secretary David Mundell said: "Whisky is hugely important to Scotland's economy, it is not just our biggest export, but an iconic product which draws visitors here from around the world.

"The UK Government is wholehearted in its support for the industry - we froze duty rates again at the last Budget, and are determined to open up new markets around the world as we leave the EU. I welcome Diageo's major new investment.

"It is hugely exciting, not just for Scotland but for whisky drinkers around the world who want to learn more about the history and traditions of our national drink."

Diageo chief executive, Ivan Menezes, said: "Scotch is at the heart of Diageo, and this new investment reinforces our ongoing commitment to growing our Scotch whisky brands and supporting Scotland's tourism industry.

"For decades to come our distilleries will play a big role in attracting more international visitors to Scotland.

"I am also delighted we will be able to bring our knowledge and expertise to help the next generation, through mentor programmes and skills training."