Heroes star Hayden Panettiere was reduced to tears when she was honoured by the Humane Society of the United States for her protests against the slaughter of whales in Japan.

The actress cried when she was given a standing ovation at the Humane Society’s Genesis Awards on Saturday, and was forced to visit the bathroom following her speech to regain her composure.

Panettiere was given the Gretchen Wyler Award, which recognizes celebrities who bring attention to animal causes, for her work with the sea-faring mammals last year.

She told the audience, "As an actress, you always dream of getting awards like the Golden Globe award, but I never expected to get an award that is this special and important to me as this.

"There are people who dedicate their entire lives to preserving the environment and defending animals, they are so much more deserving of something like this."

Beverly Kaskey, of the Humane Society, adds, "She’s an inspiring example to her generation, using her compassion, courage and celebrity to help animals in a very effective way."

Panettiere’s family and boyfriend Milo Ventimiglia - who kindly escorted her back from the bathroom - were in attendance at the event at the Beverly Hilton hotel in California.