Island I Vow is one of many small islands in Loch Lomond

The Clan MacFarlane Society is worried about the condition of Island I Vow between Tarbet and Ardlui, which was once an ancestral stronghold.

It said the island, which is barely the size of a football pitch, was suffering at the hands of vandals.

But a couple from Bo'ness, who are also Macfarlanes, believe they have the best claim on the island.

They claimed ownership of the island several years ago using a legal process for land with no official owner, and they do not want the Clan MacFarlane Society to have it.

Instead, they are considering offering it to a public body such as the National Trust for Scotland.

'Non domino title'

Brian MacFarlane, of the Clan MacFarlane Society, said it was important to preserve the island's heritage.

He added: "The MacFarlanes owned this area for 579 years from 1225 to 1784 until it was sold to pay off the debt of the chief at that time."

He said the society wanted to stop vandals from destroying the small piece of land and was best placed to care for it.

However, Dougie MacFarlane, from Bo'ness, and his wife Bernadette believe that they have the best claim on the island.

Mr MacFarlane said: "We first saw the island in 1994 in a visit and spotted the castle, which had fallen down.

"I wanted to help whoever owned the island rebuild it, but no matter how hard I tried I couldn't trace the owner, so our lawyer suggested why not try for a non domino title."