An actor said he reached “peak Welshness” working alongside Sir Anthony Hopkins and Catherine Zeta-Jones on the upcoming film A Visit to Grampa’s.

Celyn Jones said it was like a “homecoming” and a “culture moment” taking part in the film adaptation of the Dylan Thomas short story.

“I think I reached peak Welshness when I was singing Myfanwy, while Tony [Hopkins] played the piano and Catherine Zeta-Jones served the drinks,” he told Lucy Owen on Radio Wales.

“I just needed Charlotte Church to call the bingo and I’ve gone full score Welsh.”

A Visit To Grandpa’s follows a young boy sent to spend a summer full of adventure with his eccentric grandfather on a Welsh farm.

Speaking of Sir Anthony, who plays Grampa, Jones said he “was on everyone Facebook’s feed in Dolgellau” after stopping to take pictures and giving them his time.

“It was a total pleasure, a total egoless experience for me where I just thought I don’t care if I was just a disembodied arm in this film. Just being near him was great and he was great,” he said.

In April, hundreds of people gathered in Dolgellau, Gwynedd, to watch filming, while Sir Anthony has also recited a Thomas poem as an apparent nod to the film.

New pictures were released in April showing Zeta-Jones’ as-yet unnamed character alongside Hopkins.

Dylan Thomas is arguably Wales’ most celebrated writer and poet. Born in Swansea in 1914, his most notable works include Under Milk Wood and the poem Do Not Go Gentle into that Good Night.

He died in 1953 aged 39.

Jones also stars in upcoming film On the Sea, set in a remote north Wales fishing community which was filmed on Anglesey.

The story follows Jack, played by Barry Ward, a middle-aged man who lives a traditional life with his wife and son centred around fishing and the church.

Jack then starts to question his sexuality after carefree Daniel, played by Lorne MacFadyen, arrives in the village.

MacFadyen said while it was a story you hear often, it is rarely seen on screen.

“I think it’s a really fascinating character study for Jack. He’s lived his life as a married straight man all the way up to his middle age. Suddenly these other feelings start to rise to the surface that he can’t deny.

“My character has been very comfortable by contrast all his life with his sexuality. I think people will be surprised by the certain novelty of these characters, and the very touching relationship that they develop very quickly,” he said.

Jones plays Jack’s brother Dyfan who he runs a mussel family business with. He said he learned how to hand rake mussels during the film, although admitted they were unusable by the end of the day.