Image caption Chris and Colin Weir have given more than £3m in all to the Yes camp

A couple who won £161m on the Euromillions lottery have given a further £2.5m to the Scottish independence campaign in the past year.

Yes Scotland figures show Chris and Colin Weir each donated £1.25m, after a £1m donation the year before.

Overall, Yes Scotland said that it had received more than £3m in donations from April 2013 to May this year.

In December last year, the Better Together campaign said it had received £1.6m in donations since April 2013.

The pro-Union group indicated Yes Scotland was catching up with its own disclosure on donations, but said the figures showed the independence campaign relied on one "SNP source" for nearly 80% of its funding.

The independence referendum will be held on 18 September, with the official campaigning period getting under way on 30 May.

The latest Yes Scotland figures outline more than 11,000 donors who each gave up to £7,500, totalling £473,000.

A further £2,678,000 has been given in larger donations from seven individual supporters, including the Weirs.

Yes Scotland chief executive Blair Jenkins said: "We greatly appreciate and are hugely encouraged by the thousands of people across Scotland who have made donations - both large and small - according to their financial means."

Image copyright Other Image caption Voters will be asked the question: Should Scotland be an independent country?

Better Together campaign director Blair McDougall said no-one would criticise the Weirs, who are long standing SNP supporters.

But he added: "Whilst Better Together relies on the support of a broad mixture of large donors and thousands of ordinary people giving what they can, it is clear that the nationalists are almost completely dependent on one source of income."

The Better Together group figures from last year showed the biggest single donor was businessman Donald Houston, who gave £100,000 and a further £500,000 through two of his companies.

Earlier this month the Weirs explained their decision to donate funds to the pro-independence campaign.

In a letter published in some Scottish newspapers, the couple said: "We appreciate that not everyone shares our political view.

"That surely is the point of democracy. And, in a democracy, we each have the right to support political campaigns of our choosing and to contribute financially, provided we do so in line with the rules."

Meanwhile, Canon Kenyon Wright, who chaired the Scottish Constitutional Convention on devolution, has declared his support for a Yes vote in a letter to the Sunday Herald newspaper.

Canon Wright said: "The Constitutional Convention shaped the Scottish Parliament, but it left important aspects of its aims unfinished."

He added: "In Scotland's affairs final power lies either with the people of Scotland or with the Parliament and Government in Westminster. It cannot lie with both."