An American woman married to a Croydon teacher for nearly four years has been told to leave the UK because her marriage is not authentic.

Lisa Barrett, who lives with her husband Gavin on the Shrublands estate, has been told her application for a spouse visa has been refused.

Last week we revealed how the Home Office had kept Lisa's passport for more than three years and she was prevented from returning home to her father's aid after his house burnt down.

This week Lisa learned her application had been turned down because she failed to prove her marriage was "genuine and subsisting".

The 44-year-old says she is incensed that the Home Office has suggested 54-year-old Gavin uproot and move back to the US with her.

"It's crazy," said Lisa. "Gavin is a teacher but would not be able to work in the US. The only place we could stay would be my father's house, which burnt down.

"In the three-and-a-half years it has taken the Home Office to make a decision on my visa, I haven't been able to work so we are broke.

"Even if we wanted to we couldn't afford the airfare home. Someone must have made a mistake."

Lisa, who works voluntarily with elderly people in Croydon, has also been told she failed to prove she had made a life for herself here.

She arrived in the UK in 2001 on a six-month tourist visa. Shortly before it expired she was diagnosed with a benign brain tumour and advised not to travel.

During that time Lisa and Gavin fell in love and married in July 2002. In September of that year Lisa made her application for a spouse visa.

Croydon Central MP Andrew Pelling has taken up Lisa's case. Staff at his office say they are baffled by the decision.

A spokesman forthe Croydon Central MP said: "This is an injustice. We will do all we can to take this further. We intend to write to the immigration minister Tony McNulty to request her case is looked at again.

"There have been a lot of problems with letters not turning up."

A Home Office spokesman said: "A decision is made based on the information given. Immigration officers must be satisfied that the details given are factual and correct.

"In addition, overseas nationals wishing to come to the UK on the basis of marriage should apply for entry clearance from abroad."