Serena keeps 'Black Panther' catsuit

Serena Williams will continue to wear her striking, all-black catsuit in her French Open second round clash on Thursday despite questions raised over whether or not it breaks the rules over appropriate on-court playing gear.

The 36-year-old American dominated the headlines at Roland Garros on Tuesday when she made her return to Grand Slam tennis after giving birth to her daughter last year.

However, it wasn't her straight sets win over Kristyna Pliskova which got people talking -- it was her catsuit which she said made her feel like a "super hero" and a "warrior princess" with a nod to it being inspired by the "Black Panther" movie blockbuster.

"She will wear this outfit for her second match," said a spokeswoman for manufacturer Nike on Thursday.

Czech world number 70 Pliskova questioned the legality of the Williams outfit when she talked with Czech media after the first round match.

"I was wondering if it was in the rules," the Czech said.

"I don't even know what material it is, it looks like neoprene.

"They should follow the rules, otherwise play in the nude!"

However, there is no indication that the suit breaks any tournament regulations.

Australian doubles player Arina Rodionova also questioned its legality.

"Nothing against Serena's outfit, looks pretty cool actually," she tweeted.

"But just wondering how is that allowed by the rules if we only allowed to wear legging until the middle of the calf the longest, and ALWAYS have to wear skirt/shorts on top of the leggings. Were there any rules changes?"

Russian doubles star Alla Kudryavtseva said she hoped Williams's revolutionary black outfit leads to a rethink over the playing regulations.

"I've been asked to put a skirt on over leggings many times. You have no idea how uncomfortable that is. Or to take them off. That happened too. On both grand slams and WTA tournaments," she tweeted.

"I hope now we can wear leggings alone! Go Serena!"

Williams said the suit was crucial for her health and well-being, claiming it prevented the return of blood clots which left her life in danger after she gave birth to daughter Alexis Olympia Ohanian in September.