Why is Sienna wearing a wet t-shirt?

Now here's a way to attract attention for a cause. Actress Sienna Miller posed for a publicity shoot in a wet t-shirt while on a visit to India for Global Cool, a climate change awareness organisation.

The star is in the country for a week-long promotional visit to the region as part of her ambassador duties.

A day earlier, she teamed up with Bollywood star Amitabh Bachchan to urge Indians to do more to slow the effects of climate change.

Miller said people could help by turning their air conditioners down by even one degree or by turning off phone chargers and other electronic equipment when it's not being used.

"If each one of us does our bit, we will be helping to keep global warming from harming our countries," she said.

Bachchan, India's biggest movie star, announced that the Indian International Film Academy would partner with Global Cool to increase knowledge about greenhouse gas emissions.

It's already been a globetrotting month for Miller. She visited Rome to attend a Valentino party after a whistle-stop visit to New York.

The trips coincided with a controversial time: she was been blamed for the high profile break-up of American rapper P Diddy's long-term relationship with the model Kim Porter, the mother of his three children.

According to reports in the U.S., 36-year-old Miss Porter moved out of the couple's New York apartment following rumours concerning the nature of Diddy and Miss Miller's friendship.

Despite persistent rumours to the contrary, both Miss Miller, and 37-year-old Diddy have denied any romance.