A British couple is fighting to retain custody of two six-month-old girls after they paid £8,200 to an online California-based adoption agent for the twins.

Alan and Judith Kilshaw of Buckley, north Wales, travelled to the US in November to buy the baby girls from adoption agent Tina Johnson after the couple saw her advertisement on the internet.

But Johnson, who runs online adoption agency Caring Hearts, had previously sold the twins to another couple, Richard and Vickie Allen of San Bernadino, California, for £4,000. The Allens are now demanding that the Kilshaws return the girls.

In what they say is an attempt to warn other prospective clients about the dangers of paying to adopt children abroad, the Kilshaws told their story to the Sun newspaper. They said that when they arrived in San Diego last year, they paid an arrangement fee to Tina Johnson and took possession of the twins, who they named Belinda and Kimberley.

The twins had been put up for adoption by their natural mother, Tranda Wecker, 28, of St Louis, Missouri. Ms Wecker and Ms Johnson allegedly tricked the Allens into handing the twins back to Ms Wecker, telling the couple that the mother wanted a couple of days alone with her daughters to say goodbye.

Instead, Johnson handed the babies over to the Kilshaws. When confronted by the Allens' in-laws, the couple fled with the twins and Ms Wecker to Arkansas, a state with more relaxed adoption laws than California. There they finalised the adoption before travelling back to the UK at the end of December.

The Allens have contacted the FBI to investigate the matter. Meanwhile, the girls are living with the Kilshaws in Buckley on six-month holiday visas. The couple say they will fight to retain custody of the twins.

Felicity Collier, chief executive of British Agencies for Adoption and Fostering, says: "This case demonstrates why private adoption is illegal in the UK.

"We often hear criticisms by prospective adopters about the checks that are carried out before adoptive parents are considered suitable and comparisons are made with the ease with which people can adopt in the US."

She adds: "It is totally unacceptable to BAAF that children are sold to the highest bidder. It is vital that people who wish to adopt from overseas take proper advice before they enter such a minefield."

Useful links
ABC Adoptions: online adoption resources
Adoption-Net.co.uk
British Agencies for Adoption and Fostering