Whitney Houston is set to earn $2.8 million to perform at a London charity event.

The troubled star has been lined up by billionaire philanthropist John Caudwell to give a rare one-hour performance at the Cauldwell Children Legends Ball at the Battersea Evolution arena on May 8.

A source said: "Mr. Caudwell thinks it is important to raise the profile of the Cauldwell Children charity and stars such as Whitney Houston are the sort of people he's hoping to attract."

Whitney - who has battled an addiction to drink and drugs - has made few public appearances in recent years and also has a reputation for failing to turn up for shows.

Her appearance at the Swarovski Fashion Rocks event at London's Royal Albert Hall last October was her first high-profile public outing since her stint in rehab in 2006. Last December, she performed at the Live and Loud music festival in Kuala Lumpur, Malaysia.

Whitney's problems with alcohol and drugs first surfaced in 2000 when she and then husband Bobby Brown were arrested for marijuana possession at a Hawaiian airport and later fined.

Later that year, she gave just 10 minutes notice before pulling out of her scheduled performance at record producer Clive Davis' induction ceremony into the Rock and Roll Hall of Fame, amid rumors she was behaving erratically due to drug use.

Whitney was dropped from performing at the 2000 Academy Awards by the show's musical director Burt Bacharach, after reportedly singing the wrong song at rehearsals.

Whitney divorced Bobby in 2007 following 15 years of marriage.