James Mooney, 33, who worked in the Nigerian capital Lagos, claimed the domestic servant had been working for his family for a year, rather than six months, to ensure she would qualify for a visa and they would have cheap labour once back in Britain.

However, the scam was discovered by colleagues among the tight knit expat community who knew the family had sacked their unreliable maid just six months earlier and replaced her with the nanny for whom they sought a UK visa. It was cancelled before the nanny, Rose Usang Inah, could travel to the UK.

Today Mooney was sentenced to nine months in jail, suspended for two years, after pleading guilty to assisting unlawful immigration on the second day of his trial at Inner London Crown Court.

Charges against his ex-wife and mother of his two children Natasha Vukic, 36 and who worked as an Entry Clearance Officer [ECO] for the UK Border Agency in Nigeria were dropped after the prosecution offered no evidence.

Sentencing Mooney to a three month curfew with electronic tag and to work unpaid for 240 hours, Judge Ian Darling told him: "The country was entitled to expect honesty from its public servants."

He said: "You stand before me having pleaded guilty to a serious offence representing as it does not only corruption but a massive breach of trust.

"This is as tragic as it is perplexing. You come from a family who in effect has dedicated itself to public service working around the world for varying limbs of the British Government.

"Fifteen years ago you followed your parents into this world and you were successful, able and thoroughly trusted.

"In a moment of sheer madness not in my judgement carried out solely by you, you have thrown it all away.

"You have brought shame not only to yourself and to your family. Their deservedly good reputation has been tarnished by your folly."

He told Mooney his loss of integrity and job would be a "permanent reminder of your stupidity."

Judge Darling said Mooney was now facing losing his home while paying maintenance to his two children and so was nor required to pay costs of more than £9,500, £6,000 of which was the cost of sending detectives to Nigeria to investigate the crime. The maximum sentence was 14 years.

His barrister Paul Wakerley, in mitigation, said: "There had not in fact been a breach of UK immigration law.

"A visa was initially granted on the back of the application and quickly cancelled. So there had not been in fact a breach of immigration law.

"It's not suggested by the prosecution that there was not a plan for the nanny to come to the UK and work as their nanny.

"It's not a device cooked up so as to allow this lady free access to the country. The motive was greed or saving of money.

"The effect of that which he admitted or taken responsibility for is this 33-yaer-old who worked for the FCO for approaching 15 years and had good reports has thrown all that away.

"He's lost that job, he lost the job he obtained in the UK when he came back here and his employment prospects are limited by the conviction."