Iona, who is 28 and lives in West Hampstead, London, held a pose called the “Marinelli bend” for 33 seconds, beating the existing world record by 11 seconds.

The Marinelli is an inverted back-bend where the whole body is supported by the mouth by gripping onto a short post that is held between the gums.

Iona was born and raised in Mongolia and has over 19 years of experience as a contortionist and has traveled the world performing in over 16 different countries at gala evenings, theaters, cabaret shows and on television.

She first dreamed of becoming a contortionist when she was five years old when a television performance inspired her.

Iona is implausibly bendy and is also capable of twisted headstands, scales and multiple body folds.

Iona was one of seven children born to a policeman and a nurse. She is currently studying for a law degree at Birbeck College, part of the University of London. She claims she is the only person in the UK who can do the Marinelli bend.

Of her Guinness World Record attempt, Iona said: “It’s not painful – if it was I wouldn’t be here now. But there are very few people that can do what I am about to do, so don’t try this at home.”

After witnessing Iona break the record, presenter Steve Jones said: “Guys, you are not going to believe this – it is incredible!”

The feat will be broadcast on the Sky 1 show ‘Guinness World Records Smashed!’ on May 31 at 8pm.