Liza Minnelli has left rehab.

The 69-year-old actress checked into a clinic last month seeking treatment for substance abuse but has now returned home and is focusing on returning to work.

Liza was seen on Sunday (19.04.15) at 'Real Housewives' star Lisa Vanderpump's Hollywood restaurant Pump with an unnamed pal, though it is not believed the two women know each other.

A source told the New York Post newspaper's Page Six column: ''She has been going out frequently in LA.

''She's starting to gear up to go back onstage. Her first concert will be July 24 in Biloxi, Missouri.''

Liza last attended rehab in 2004 and has openly battled with addiction in the past.

In the 1980s, she sought help for her alcohol and prescription drugs addiction following the tragic death of her mother Judy Garland, who passed away in 1969.

Liza's addiction to alcohol is said to be one of the reasons why her marriage to David Gest broke down.

Court papers filed by David in 2002 claimed that abusive and alcohol-fuelled incidents took place during their marriage.

Meanwhile, Liza previously opened up about the ''disease'', saying she had ''inherited'' it from her mother.

Speaking in 2008, she said: ''My whole life, this disease has been rampant. I inherited it, and it's been horrendous, but I have always asked for help.''