Amid disbelief that ‘chemical attacker’ was allowed to stay in Britain… BBC editor who was hired as an expert witness to help 15 Somalian criminals stay in the UK and fight deportation – including a vile offender who sexually attacked a deaf teenage girl. quits the BBC after shocking Mail exposé.

Last year, The Mail on Sunday exposed how Mary Harper, Africa Editor for the World Service, was paid to give expert witness evidence for Somali gang rapist Yaqub Ahmed during his five-year legal battle to stay in the UK.

Now an investigation by this newspaper can reveal Ms Harper has given expert witness evidence in a string of other controversial deportation appeals by Somali offenders – including for another three sex attackers, three drug dealers and a career criminal who spent a decade in British jails.

Following a series of questions from the MoS, the BBC last night announced that Ms Harper was leaving the Corporation, but refused to say whether she had been sacked or had quit.

In one of the most shocking cases, Ms Harper warned that a Somali man who committed a horrific sexual assault on a profoundly deaf 17-year-old girl would be at ‘severely heightened risk’ if he was sent back to Somalia because he had committed a sex crime.

A judge disagreed and threw out his appeal against deportation. Astonishingly, this newspaper has discovered that, 16 months later, the 29-year-old attacker, who the MoS is banned from naming by a court order, has still not been kicked out of Britain and is living with relatives in a council flat.

The shocking revelations come just days after it emerged that an Afghan man currently on the run after a horrific chemical attack was granted asylum despite having a conviction for sexual assault.

Ms Harper’s extensive work as an expert witness last night plunged the BBC into an impartiality row.

Tory deputy chairman Rachel Maclean MP said she was ‘flabbergasted’ at the number of immigration cases Ms Harper had been involved in and demanded the Corporation review its guidelines.

‘What are the families of those affected by these criminals thinking when a BBC employee is giving evidence to say they should stay in the country?,’ she said. ‘To me there is something very wrong with that.’

Our exclusive investigation also reveals how:

Ms Harper suggested that a violent criminal convicted of assault and robbery would be at risk from terrorists in Somalia as his tattooed arms would be seen as a ‘sign of homosexuality’;

She claimed another prolific criminal would face ‘great difficulties’ in Somalia due to a lack of family and financial support – despite the court hearing the offender’s mother had enjoyed three holidays to Dubai;

Ms Harper warned a third criminal’s long history of offending in the UK – 39 convictions for 80 crimes over 17 years – would result in him being shunned by his clan if he returned to Somalia;

A Somali who flooded a Hampshire town with drugs was allowed to stay in the UK after Ms Harper gave evidence. Ahmed Ali Jama, 29, claimed he would be in danger in Somalia because his father and sister are popular singers;

Judges twice questioned Ms Harper’s objectivity and in a third case branded some of her evidence ‘speculative and not supported by any broad range of views’;

In another tribunal, the Home Office said information she had mistakenly attributed to a terrorist source was ‘in fact obtained from an office cleaner’.

Educated at £42,000-a-year Bedales School in Hampshire, Ms Harper became a BBC Africa Editor in 2009. The mother of two first visited Somalia in 1994 at the height of its civil war and has written books about the nation and the Al-Shabaab terror group.

On her website, she describes herself as ‘an expert witness in Somali-related legal cases’ as well as referring to her BBC job.

Court papers reveal she has been providing expert witness evidence in immigration cases for at least a decade, and has links with Wilson Solicitors, the London law firm that represented Yaqub Ahmed during his relentless cycle of dubious human rights appeals.

Ahmed, 34, who was jailed in 2008 for raping a 16-year-old girl, was deported last August – five years after his removal was thwarted following a mutiny of virtue-signalling passengers on the same flight.

The MoS has identified 12 immigration cases in which Wilson Solicitors asked Ms Harper to either write a report or give evidence in court.

Despite repeated requests, Ms Harper and the BBC have refused to disclose how much she has been paid to give evidence. Legal sources say expert witnesses can be paid up to £2,500 for producing a report in legal-aid-funded cases.

Seven of the 15 Somali criminals whose cases involved evidence from Ms Harper were successful in their appeals. The Home Office last night refused to say how many of the others have been deported.

In 2019, Ms Harper provided evidence during a bid to block the deportation of a Somali who had been jailed for seven years for an appalling sex attack….