Evelyn Calcabrini was due to stay in Wales to learn the language
A woman has been sent back from the UK to Patagonia after immigration officials refused to believe she was travelling to Wales to learn Welsh.
Evelyn Calcabrini, 20, was heading to Glyndyfrdwy, Denbighshire, to stay with a local couple for six months.
MPs are going to raise the matter with Welsh Secretary Peter Hain. The UK Border Agency said it ran a "firm and fair" system.
There has been a Welsh settlement in the South American region since 1865.
After a flight lasting approximately 15 hours, Ms Calcabrini arrived at London Heathrow on 25 May, a Bank Holiday.
We will continue to have these problems unless the Immigration Service understands what the link between Wales and Patagonia is
Hywel Williams MP
Two Plaid Cymru MPs, Elfyn Llwyd and Hywel Williams were contacted and asked to intervene when she was refused entry.
Mr Williams, MP for Caernarfon, said Ms Calcabrini had arranged to stay with Eos Griffiths and his Patagonian-born wife Carina, at their home in Glyndyfrdwy.
She had a letter from the couple, confirming they would support her during her stay in the UK.
However, she was told she could not stay in the UK and was sent home.
Elfyn Llwyd, MP, said he was angry at how Ms Calcabrini was treated
Mr Williams said: "I spent four hours on the phone trying to sort this out, trying to get hold of someone at the Home Office, and drew a blank.
"They reviewed the decision internally, they said, but there was no shifting on the decision."
He said the treatment of the woman had been "disgraceful".
The link between Patagonian and Welsh people dates back to 1865, when about 150 settlers sailed from Liverpool to Argentina in the hope of establishing a colony and preserving Welsh language and culture.
Mr Williams added: "It's a matter of not just blood, but culture.
"We will continue to have these problems unless immigration officials understand what the link between Wales and Patagonia is."
Mr Williams said both he and MP Elfyn Llwyd hoped to raise the matter with Peter Hain at Welsh questions on Wednesday.
A UK Border Agency spokesman said: "We have strict rules in place to protect Britain's border and the responsibility rests with applicants to demonstrate they meet the requirements of these rules and will comply with any conditions attached to their leave.
"Where they do not, entry will be refused. The system is firm and fair, and it applies to everyone."
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