Jennifer Lopez insists she has never had any plastic surgery.

The 'Dance Again' hitmaker has hit back after a British plastic surgeon, Dr. Ayham Al-Ayoubi, suggested she ''showed many signs'' of having work done to her face.

The 44-year-old star was clearly unimpressed with his medical opinion and tweeted: ''@DrAyoubi Sorry Sir, but I have never had plastic surgery of any kind. #fact''

The actress responded to the plastic surgeon, who is based in London, after he tweeted a split-screen photographs of her and wrote: ''These before and after pics of @JLo show many signs of #plasticsurgery - naturally pretty but now looks amazing.''

He later added: ''U are naturally a very beautiful woman and look great, sometimes clever makeup can enhance features slightly changing their appearance @JLo''

But following Jennifer and her fans' reaction, the medic claimed his assistant was responsible for the tweets.

He wrote on Tuesday (05.11.13): ''Dear @JLo I wonder if you can accept my sincere apologies about the wrong tweet which was written by my assistant without my knowledge....

''I sincerely apologise to @JLo & her fans. I want to remind everyone it was NOT me who sent that wrong tweet! it was my assistant. (sic)''

The 'American Idol' judge recently revealed that she learnt to stand up for herself from an early age as she was criticised for her appearance and curvy figure early in her career.

She said: ''You have to stand up and say, 'There's nothing wrong with me or my shape or who I am; you're the one with the problem!' And when you can really believe that, all of a sudden other people start believing too.''