The chairman of Scottish Natural Heritage has been forced to reject an accusation that government ministers interfered in an exercise to map wild land in case it frustrates the development of onshore wind energy.

Conservative MSP Jackson Carlaw asked Andrew Thin to explain why maps have not been made public, raising his suspicion that the publicly funded body has been "nobbled".

The exchange took place at Holyrood's Public Petitions Committee during discussion about a plea by conservationists the John Muir Trust to protect wild land from inappropriate development.

Mr Thin said several maps have been prepared to advise ministers about potential updates to planning regulations.

Mr Carlaw said: "The suspicion you see is that the reason we don't have a map is because you produced a map, ministers saw it and because it was going to interfere with plans for the development of onshore windfarms, conversations then took place that said 'we simply can't have this, we can't have this in the public domain, we can't possibly put statutory provision in place around all of this because it is going to interfere with our energy policy'.

"Have any such conversations at any time taken place?"

Mr Thin said a number of conversations have taken place with officials but told Mr Carlaw: "Not of the character you have described."

Asked for a guarantee there were no conversations of that nature, he replied: "Not to my knowledge at all."

MSPs focused on wind energy in their discussions, despite a call to think beyond turbines when considering protection of land.

Ian Jardine, chief executive of Scottish Natural Heritage, said: "We've seen the issues historically around commercial forestry, about large-scale hydro developments, about telecoms masts.

"The point I'm making is that policy I don't think should be simply about windfarms. It's a debate about how much of Scotland's upland landscape would the Government wish to apply particular planning policies to, because of its nature and its character, which is not just about windfarms."

The John Muir Trust collected thousands of signatures from people who back its concerns about the rate of development across otherwise unspoilt areas.

In a submission to the committee, the trust stated: "Wild land in Scotland provides important ecosystem services, sustaining numerous forms of life including key biodiversity species and providing for essential climate change mitigation and adaptation, for instance, retention of carbon in peat, providing high-quality water supplies and contributing to natural flood defences.

"Wild land does not receive clear and explicit recognition or protection within the Scottish planning system, or when decisions are made on sustainable land use.

"As a consequence, as more accessible and less sensitive sites are developed, some of the best wild land faces the threat of being lost forever."

The trust says it cannot afford to step in and challenge every planning application it thinks is inappropriate.

The committee decided to ask Environment Minister Paul Wheelhouse to come to a future hearing.