Billionaire US presidential hopeful Donald Trump is raking in millions from his two Scottish golf resorts.

Despite a public spat with former First Minister Alex Salmond over windfarms, the colourful tycoon has continued to invest in Scotland and documents reveal just how much cash they are generating. 

Formal disclosures made as part of his controversial American presidential campaign, show that Mr Trump is pulling in $25 million (£16m) a year from his two high-profile ventures.

A 92-page document lodged with the Federal Election Commission shows that Mr Trump's income from his latest Scottish acquisition is among his most lucrative.

His Turnberry resort in South Ayrshire made $20,395,000 in income last year, according to the document, which was filed last week.

That is £13m at current exchange rates. Only one other golf resort in Mr Trump's portfolio, in Florida, makes the tycoon more.

Mr Trump's International Golf Links in Menie, Aberdeenshire, made a more modest $4.35m or £2.8m.

Both assets are valued at "more than $50m" in the paperwork, which fails to demand precise valuations.

As such, the document does not establish Mr Trump's widely publicised claims to be worth $10bn.

The disclosures have sparked huge interest in the Trump empire in the United States, where Mr Trump leads in the polls for the Republican nomination for the presidency despite - or some say because of - remarks that Mexicans were sending "rapists" to America as illegal migrants.

Revelations include that he received just $201 in royalties from his book "How to Get Rich" last year.

The 69-year-old, whose mother was Scottish, has previously said he believes that windfarms are as big a disaster for the country as the Lockerbie crash in 1988.

He threatened to pull out of his Menie development - which had sparked environmentalist protests - because of offshore turbines to be built within sight of the resort.

His criticism of Scotland, however, did not stop him investing in Turnberry. He bought the hotel and golf course last year for an undisclosed sum and pledged to invest at least £100m in turning it in to "the finest resort of its kind anywhere in the world".

Mr Trump's remarks on Mexicans, however, risked the resort's status as a host of the Open Championship.

Organisers are concerned his alleged racism would hurt the brand, especially as they seek to promote the sport in the Spanish-speaking world.

This week it emerged that despite his protests against windfarms, Mr Trump had invested in the technology. He said the investments were made on his behalf by brokers managing his wealth.

Scottish environmentalists, however, accused the billionaire of hypocrisy. Lang Banks, director of environmental group WWF Scotland, said: “Those looking after his investments have clearly realised what Trump himself hasn’t – namely that that wind power not only works, but is a sound investment for the future."

Patrick Harvie MSP, co-convener of the Scottish Greens, said: "The more we learn about this greedy, racist bully, the more ashamed we should be of letting him establish any presence at all in Scotland.

"The sooner we see the back of him, the better."

David Watt, of the Institute of Directors in Scotland, said: “We would welcome any investment in growing the economy. A certain individual may not please everybody. But he has put money in assets the future of which may not have been quite so rosy without him.”