Scotland's second-biggest private landowner and Scottish ministers are facing calls for greater transparency over a deal that involved an exchange of land 150 miles apart.

Anders Holch Povlsen, a Danish billionaire who owns 150,000 acres, bought land in the Borders to give it to the Forestry Commission, in return for Highland woodland near to one of his estates.

Land reform campaigners who monitor transactions say while exchanges of land are not unknown, the distance between the areas sets the exchange apart.

The deal which involves Mr Povlsen getting 1000 acres to add to his 43,000-acre Glenfeshie Estate, south of Aviemore, is just the latest involving the controversial figure who has been buying other Highland estates in recent years.

Mr Povlsen, a clothing magnate, has been criticised for aggressive deer culls on Glenfeshie in his efforts to regenerate native woodland and conserve indigenous species such black grouse and capercaillie. The estate says this conservation work will benefit from the deal.

With the acquisition of the 20,000 acre Gaick estate in Inverness-shire at the start of the year, the Dane's land portfolio was second only to that of the Buccleuch Estates, with an estimated 280,000 acres.

In the deal that has now come to light, in return for the 1000 acres handed to Mr Polvsen, Forestry Commission Scotland (FCS) gets three areas of land: the leasehold of the 750-acre McAlpine plantation near Loch Morlich and three small adjacent woodlands; a 138-acre plot in Strathspey; and 336 acres of plantable land in Peeblesshire near Walkerburn.

It is the purchase of this land 150 miles away from Glenfeshie which has raised eyebrows. The Glenfeshie Estate did not originally own it but bought it specifically to hand over to use as part of the overall deal.

Land reform campaigner Andy Wightman said it was quite unusual for Scottish ministers in the form of FCS to get land in deals like this, particularly when the parcels of land are so far apart. He called for greater transparency.

"I think we need to know why this happened because FCS and Scottish ministers are perfectly free to enter the land market themselves and are doing so, buying land in the likes of Perthshire and Stirlingshire.

"So why on this particular occasion did they need an estate to buy it for them?"

Meanwhile, correspondence in the local press called on FCS and Mr Povlsen to explain the transfer of local land to Glenfeshie Estate.

Mr Povlsen bought Glenfeshie in 2006 and has already extended it by about 4000 acres, buying the neighbouring farm of Killiehuntly.

In 2008 he bought the 30,000-acre Braeroy Estate, near Fort William and in 2011 bought the 24,000-acre Ben Loyal estate and the 18,000-acre Kinloch estate near Tongue, both in Sutherland.

Mr Povlsen lives in Denmark. His estimated £4 billion fortune makes his family the second wealthiest in Denmark, behind the Maersk shipping dynasty.

Thomas MacDonell, director of conservation at Wildland Ltd, which runs Glenfeshie for Mr Povlsen, explained the estate's thinking behind latest deal: "There were very sound environmental and land management reasons for both the estate and FCS to simplify the boundaries between them and we were happy to an reach agreement. This will assist us to further improve the habitat for our thriving woodland grouse population."

He said it was also in the interests of both parties involved to include the purchase of land in the Borders.

An FCS spokesman said: "These exchanges have smoothed woodland boundaries and merged 'islands' of woodlands with surrounding forest to create more unified areas that allows us, and the Glenfeshie Estate, to develop a more cohesive, effective and over-arching management plans.

"This will help our woodland creation and restoration plans as well as our conservation work."

He said another bonus was that the Borders site would allow heavy timber traffic to be re-routed away from the village of Glenbenna. He said it had been the estate's decision to buy this site.

l Anders Holch Povlsen lives with his wife and three children in Denmark.

l His parents opened the family's first store in 1975 in the Danish town of Ringkobing.

l At 28 he took over the family fashion retail business Bestseller.

l Last year it had a turnover of £2 billion.

l It employs more than 12,000 people and works with supermodels such as Helena Christensen, Kate Moss and Claudia Schiffer.

l He has substantial farming interests in his home country and owns areas of forestry.

l He has bought land in the Carpathian mountains in Romania to establish a wilderness reserve as wolves, bears and lynx survive there.