Scotland's richest people got richer over the last year, with a record number of billionaires.

The number of Scots among Britain's wealthiest people reached a 10-year high, with 78 joining the ranks in the annual Rich List from the Sunday Times, compared to 74 last year.

The number of Scottish billionaires has grown from two to six in two years, with Mahdi al-Tajir, head of the Highland Spring mineral water firm named as Scotland's richest person, worth £1.65 billion.

The 81-year-old former UAE ambassador to the UK has a 24,000 acre estate near Gleneagles, Perthshire, and splits his time between there and London.

He is the 44th richest person in the UK and has interests in metal, oil and gas trading and a large property portfolio, as well as running Highland Spring.

He is joined on the list by the Grant and Gordon whisky family, worth £1.4 billion, oil tycoon Sir Ian Wood, worth £1.2 billion, the Thomson family, whose DC Thomson publishing company is valued at £1.1 billion, Alastair Salveson, and his family, who have a £1.05 billion share of Aggreko, the Glasgow plant hire firm, and businessman Jim McColl, worth £1 billion.

The combined wealth of Scotland's 100 richest people amounts to a record £21.1 billion, almost double the level in 2004.

List editor Ian Coxon said: "The Rich List shows that business is booming in Scotland, from Aberdeen to Ayr.

"The good news for the country's economy is that much of the £21 billion wealth accrued by the top 100 millionaires has been made by generating worldwide demand for Scottish products and knowhow."

The entry point for Scots into the list has risen from £52 million to £75 million, with new entries including lottery winners Adrian and Gillian Bayford who have a £149 million fortune.

Overall, Britain's wealthiest people have a combined fortune of £450 billion.