Amber Heard left an awards ceremony before picking up her prize because of an "emergency"

According to E! News, Amber had seemed fine as she walked the red carpet, but appeared "distressed and uncomfortable" within the venue.

Cara and iO picked up Amber's award from Ayaan Hirsi Ali, a Somali-born Islam critic and former Dutch politician, and made a speech praising their pal.

iO said: "Our dear friend Amber unfortunately suffered a bit of an emergency earlier this evening and she had to go.

"And I want to also say that I've never seen Amber nervous and I've known her quite intimately for a long time. And she's met pretty much everyone that you could be starstruck by. But Ayaan Hirsi Ali is as close to God as you could get for her, so to know that Ayaan was here and for her to have to leave anyway means that it was a very serious emergency.

"We both are hoping that she's OK."

iO later praised the 30-year-old beauty for donating part of her $7 million divorce settlement from Johnny Depp to the ACLU, with the remainder going to the Children's Hospital of Los Angeles.

iO said: "[She] went through one of the most publicised divorces of last decade probably, and all of her 'winnings' from that divorce, as many would've called it, because many pegged her as a gold digger, she donated to the ACLU."

And the pair also read out parts of Amber's speech in her absence.

iO read: "As an activist and human, as someone who is intrinsically allergic to justice, I am humbled and honoured to be here tonight among so many dedicated world-changers and real life heroes.

"One of which is my hero, Ayaan Hirsi Ali, who has so graciously donated her time and energy to present this award to me. Having you here tonight is a gift for which I will forever ill equip to adequately pay back."

Cara added: "So she wants to thank everyone here tonight for their dedicated pursuit of justice and concentrated efforts for making this world a better place."