The designer, whose wares have been worn by celebrities including Rihanna and Olivia Palermo, told the Daily Telegraph that while she had once befriended Bingle, she would soon be taking up the issue with Cotton On.
"I haven't spoken to Lara since her collection has come out ... I was planning on seeing her and bringing it up," she revealed.
"I don't know how much power she has with a big company like Cotton On (Clothing)."
While Lisa Marie's zip-front swimsuit retails for around $330, Lara's one-piece costs just $29.
A source close to Bingle told the Mail Online that Fernandez' accusations are "just a grab for attention".
A representative for Bingle had no comment when contacted by the Mail Online.
A spokesperson for Cotton On said they hadn't received any communication from Lisa Marie Fernandez.
"Ms Fernandez has not contacted the Cotton On Group to explain her concerns," the spokesperson said.
"If Ms Fernandez chooses to progress this matter, Cotton On will vigorously defend the proceedings and it will enforce its right to protect its reputation and the integrity of the Cotton On Group's experienced in-house design teams."
Fernandez says she'll be taking up the issue Cotton On as well as other swimsuit labels this week.
Lara's next project is an underwear collection launching in March.
Check out the questionable designs for yourself. The images below were sent to the Herald Online from the executive assistant at Lisa Marie Fernandez:
- DAILY MAIL