Sinéad O'Connor's cause of death revealed

Sinéad O'Connor died of chronic obstructive pulmonary disease and asthma, her death certificate has revealed, a year after the Irish singer and activist died aged 56.

O'Connor's first husband and close friend John Reynolds registered the death certificate in London last Wednesday.

The document noted that O'Connor died of "an exacerbation of chronic obstructive pulmonary disease and asthma, together with a mild lower respiratory tract infection."

O'Connor died on July 26 last year at her home in south London, where police found her "without signs of life." A coroner ruled in January that she had died of natural causes.

O'Connor's career spanned three decades and saw her achieve global success with her cover of Prince's Nothing Compares 2 U in 1990. She became known as an outspoken activist, including famously tearing up a portrait of Pope John Paul II during an appearance on Saturday Night Live in 1992.