Pop legend Sir Paul McCartney has donated $2m (£1.25m) to two US hospitals that cared for his late wife Linda when she was dying from breast cancer.

The Memorial Sloan-Kettering Cancer Center in New York and the Arizona Cancer Center in Tucson, Arizona, will receive $1m (£625,000) each.

"Linda's doctors were all great and managed to alleviate suffering which she might otherwise have had," the former Beatle said in a statement.

"I want to help them continue that work for the benefit of others and to enable them to study the possibilities of alternative treatments."

In keeping with the McCartneys' belief in animal welfare, none of the money will be used to fund animal research.

The gifts will fund new research on the effectiveness of botanical medicines and holistic therapies.

Dr Larry Norton, of Sloan-Kettering's breast cancer unit, said new research required "total dedication" and "commitment to the total person, which must now include complementary and integrative 'alternative' medicine."

Linda McCartney died aged 56 in April 1998 at the McCartney family's Arizona estate.