Jessica Ennis-Hill has again expressed her serious concerns over the Zika virus as she prepares to defend her Olympic heptathlon title in Rio.

The outbreak of the virus, which evidence has shown can lead to birth defects in babies, has led some female athletes to consider whether to compete in the Games in Brazil.

World champion Ennis-Hill, who gave birth to her first child in 2014, is taking advice from the British Olympic Association (BOA) ahead of what is set to be her last Olympics.

"It is worrying, really concerning. I have to make sure I understand what's happening and what the risks are. It’s something I have to be on top of," the 30-year-old told the Daily Telegraph.

"I am receiving updates from the BOA and seeking as many bits of advice as I can get. Things are changing constantly. 

"I just want to be prepared and know what the situation is. It’s definitely something I'm keeping my eye on, because I want to know as much as possible."

Ennis-Hill's coach, Toni Minichiello, called on the BOA to move a pre-Olympic training camp to outside Brazil back in February.

United States goalkeeper Hope Solo, one of the most outspoken athletes against the Olympics after the outbreak of the virus, this month announced that she will participate in the Games after doing "a lot of research".