Marie Auma told a court that officers and staff at Southwark Police Station conspired to bully her - with two officers regularly breaking wind near her in a "primitive" and "loud" manner.

The 57-year-old, who was at American President Obama's inauguration in 2009, claims she was constantly belittled and humiliated between 2007 and 2009.

The harassment began in 2007 when she was refused leave to visit her two brothers' graves after they died in a car crash in Kenya and ended in her being medically retired with mental health difficulties, the court heard.

Ms Auma, of Green Lanes, Palmers Green, north London, is fighting for £400,000 compensation in a trial at Central London County Court. The Met denies liability.

Judge Simon Freeland QC heard Ms Auma, whose job involved liaising with crime victims on the Telephone Investigations Bureau, had been the victim of "21st Century bullying."

Describing how colleagues would break wind next to her, Ms Auma said: "This was happening on the telephone investigation desk.

"It became a common practice and nobody was investigating this behaviour.

"It was two of them - PC Andy Whiting and Ray Clement - who would do this kind of behaviour.

"PC Whiting was passing wind when he came and stood right in front of me, passing wind in a very primitive way. It made a "brrrp" noise. 

"He would come and stand right in front of me and blew the wind loudly and then left.

"It was normally when I was on a late shift that they would behave in that manner."

However, Iain Daniels, representing the Met, suggested: "This was a matter to laugh about, rather than become upset about."

Ms Auma responded that it happened "so often that it was upsetting."

Mr Daniels then suggested: "This piece of childishness didn't in fact happen, did it?"

The court was told Ms Auma also received an increase in "rude" emails across 2007 from colleagues, including PC Whiting, which prevented her doing her job.

According to her barrister, Lorraine Mensah, a Fairness at Work investigation uncovered a "stack" of emails supporting this claim, but these have since been destroyed.

"They were rude emails but not emails which I have now to hand," Ms Auma said.

"I had an increase in these emails and people on the desk noticed that.

"I could not get on with my other jobs in the morning because I had to deal with these emails."

Mr Daniels countered: "I am going to suggest that if this was a campaign against you then Andy Whiting was not a part of that. 

"If you were getting more emails than other people it was because your work was not of a good standard.

"There were concerns over the consistency of your CRIS (Crime Report Information System) reports because you were not filling them out properly."

The court heard that Ms Auma was often asked to go on "inappropriate" breaks while filling out CRIS reports, and she was subsequently logged out of the system half way through her work.

Speaking of her line manager, DS Andy Rowley, Ms Auma said: "He used to single me out and tell me to take breaks when I was in the middle of my reports, asking me to take inappropriate breaks."

Asked whether he perceived this as part of a conspiracy to disrupt her work, Ms Auma responded: "Yes, that's how I saw it."

When Mrs Auma's two brothers died in Kenya in a car crash in early 2007 she took two weeks compassionate leave, something she claims was interrupted by unnecessary calls from HR about her health and DS Rowley asking whether he could visit her home.

"These were a series of unnecessary questions being asked when I was going through this," Mrs Auma said.

Mr Daniels responded: "These questions were not inappropriate.

"It was just the way you were feeling. These management actions, we would suggest, were perfectly appropriate, which you saw through the lens of your awful bereavement.

"So when somebody asked about your health, because of how terrible the bereavement was, you felt like somebody was attacking you.

"What you perceived as bullying and harassment was really just a product of the terrible tragedy that you had suffered in 2007.

"All those inquiries about your health were not harassment." 

Ms Auma is related to Mr Obama through her aunt, Kezia Obama, who is the president's Bracknell, Berkshire-based step-mother.

Mr Daniels said Ms Auma had booked her trip to Kenya without first getting permission.

He said senior staff had refused her leave before she even bought the flight ticket.

The High Court hearing continues.