Media playback is unsupported on your device Media caption Doctor Who star Matt Smith and co-star Jenna Coleman talk about meeting Prince Charles during the visit to the BBC Wales drama studios in Cardiff

The Prince of Wales has been offered a role in Doctor Who after impressing the show's writer with his Dalek voice.

Prince Charles and the Duchess of Cornwall were on a visit to the set at BBC Wales' Roath Lock studios on day three of their summer tour of Wales.

Prince Charles tried his hand at being a sci-fi baddie by uttering the Daleks' famous "exterminate" catchphrase into a voice modulator.

Writer Steven Moffat thought he was "great".

He said: "I haven't thought about how I could weave a meeting between the Doctor and the royal family. But Prince Charles's attempt at being a Dalek was great.

"There would be a part in the show for him if he wanted it."

During the visit on Wednesday morning, the royal couple was greeted by BBC Wales director Rhodri Talfan Davies in Cardiff Bay - where Doctor Who is recorded - and then posed for pictures with two gold-coloured Daleks.

Media playback is unsupported on your device Media caption Prince Charles tried his hand at being a sci-fi baddie by uttering the Daleks' famous catchphrase "exterminate" into a voice modulator

The couple also met Matt Smith, who currently plays the Doctor but is stepping down, and Jenna Coleman, who plays his companion, as well as series head writer Mr Moffat.

The tour included the set of the Tardis, the Doctor's time travelling ship, as well as a display of some of the show's monsters, including a weeping angel and a cyberman.

Nicholas Briggs, who voices the Daleks, demonstrated some of their famous catchphrases, while production staff showed how a green screen set is used to generate some of the programme's special effects.

Doctor Who is celebrating its 50th anniversary this year.

In addition to Doctor Who, Roath Lock is also home to BBC programmes including Casualty, the Welsh-language drama Pobol y Cwm and children's drama Wizards vs Aliens.

Image caption Prince Charles and the Duchess of Cornwall meet a Dalek

Prince Charles has also visited the new headquarters of his charity, Prince's Trust Cymru where he met volunteers, staff and young people.

A Clarence House spokeswoman said Charles was very passionate about the organisation.

She said: "The new Prince's Trust Cymru headquarters will support 3,500 vulnerable young people across Wales this year, giving them the skills and confidence to turn their lives around and move into jobs.

"It's significant because in Cardiff alone, more than one in four young people (30%) are struggling to find a job (Office for National Statistics).

"The Prince's Trust Enterprise programme is celebrating its 30th birthday this year. It has helped 80,000 young people become their own boss since 1983.

"It's worth noting that three in four young people on Prince's Trust programmes move into work, education or training."

During the official opening, Prince Charles addressed young people, staff, volunteers and supporters.

He said: "I hope some of you here today are beginning to benefit in a small way and I am also incredibly proud of the difference the trust can make to so many lives."

One of the young people who met the Prince was 27-year-old Sarah Hillier, from Pontypool.

She is about to launch a custom-made teddy bear business with support from the trust.

Mrs Hillier presented Prince Charles with a bear created for his soon-to-be-born grandchild. Mrs Hillier decided she wanted to run her own business after running a successful cafeteria at her partner's workplace.

She had to leave when her husband was made redundant and she found herself unemployed.

Describing the bear she created for the Duke and Duchess of Cambridge's baby, Mrs Hillier said: "The bear is one of my favourite designs and I have chosen a soldier's outfit for it. I just hope this little bear is fit for a prince - or a princess!"

The charitable theme also continued for Camilla as she visited the Emmaus Charity shop in Porthcawl, Bridgend, which supports homeless people by giving them accommodation and work experience in a bid to turn their lives around.

On a visit to Treharris near Merthyr Tydfil, Prince Charles called in at the Farmers' Co-operative Shop and met staff and local farmers.

On Monday the couple visited the last home of poet Dylan Thomas in Laugharne, Carmarthenshire, and on Tuesday held a series of engagements in north Wales.