A portrait of a famed Welsh folk singer has gone missing while on route to an auction.

The portrait of Dafydd Iwan, by South Wales artist Dan Llewellyn Hall, went missing on its way to an auction to benefit the Yes Cymru campaign in Cardiff.

The painting, entitled ‘Rouser at the Red Wall’, was unveiled at the Wynnstay Hotel in Machynlleth on April 2 as part of the Amdani Machynlleth Literature and Travel Festival.

The painting is thought to have been lost in transit, after it was set to be the highlight of the prestigious “Welsh Sale” organised by Roger Jones auction house.

‘Rouser at the Red Wall’ captures the moment Dafydd Iwan performed a rendition of ma o Hyd before the football World Cup play-off semi-final between Wales and Austria at Cardiff City Stadium in March.

The performance left such an impression that Mr Llewellyn Hall tried to capture part of the moment in which thousands of Wales supporters joined in singing the protest song.

As esteemed portrait artist, Mr Llewellyn Hall once painted the Queen in 2013, becoming the youngest official portrait artist to do so.

Some of his other renowned subjects include paintings of First World War veterans, the late singer and songwriter Amy Winehouse and a portrait of celebrated Welsh travel writer Jan Morris, which is also on display at Machynlleth’s Wynnstay Hotel.

The artist has expressed ‘mortification’ that the 4ft painting could have disappeared while in transit.

He said: “The portrait marked a moment in the story of Wales and a pivotal moment for the language.

“The subject - Dafydd Iwan, occupies a special place as one of Wales’ foremost singer and songwriter.

“The moment depicted Dafydd’s rousing Yma o Hyd being sung by the wall of Welsh football fans."