Click here to see Jennifer's changing style over the years
"Sorry Sir, but I have never had plastic surgery of any kind,' the 44-year-old wrote after a post was sent from the account of London-based surgeon Dr. Ayham Al-Ayoubi.
The doctor, who specialises in facial and laser surgery, posted a split of an older and more recent picture of the star, and captioned it: "These before and after pics of @JLo show many signs of #plasticsurgery - naturally pretty but now looks amazing."
The entry was removed, however, after the singer's fans complained about his comments. He went on to apologise, saying the pictures had been posted in error.
"Dear @JLo I wonder if you can accept my sincere apologies about the wrong tweet which was written by my assistant without my knowledge…."
J Lo with her twins Max and Emme and boyfriend Casper Smart
He also suggested that strategically applied makeup could be behind the perceived changes between the pictures.
"U are naturally a very beautiful woman and look great, sometimes clever makeup can enhance features slightly changing their appearance @Jlo," he commented.
Jennifer, who is mum to five-year-old twins Max and Emme from her marriage to Marc Anthony, is a Loreal spokeswoman, and her makeup artist Mary Philips has said the company's foundation and powder have worked wonders for her client.