THE "Downton Abbey effect" is being credited for an early tourism bonanza at one of Scotland's oldest castles.

Visitor numbers at Inveraray Castle in Argyll, which has featured in the hit drama, have soared by almost 20% year-on-year, with a surge in interest from Americans.

And while the new tourist season is barely a month old, managers hope the popularity of the show will create a record year for the 265-year-old pile.

It comes as the castle's owners, the Duke and Duchess of Argyll, reveal they have been given special permission to use their Downton links as part of a year-long tourism drive.

New publicity leaflets for Inveraray, on the shores of Loch Fyne, feature images of the ITV cast along with the words: "Downton's spectacular Scottish setting."

Jane Young, castle manager, said: "We are being inundated by tour companies keen on hearing all about the Downton side of things.

"Many of them are UK-based jet-setters, but we've also had a very big response from the US market in particular."

The leaflets featuring the Downton cast have been placed in information centres and hotels around Scotland.

Inverary Castle had a starring role as the fictional Duneagle Castle in the series' Christmas special last year, as the Granthams and Crawleys headed north from their Yorkshire bolthole.