'Party Rock Anthem' Singer Lauren Bennett Celebrated at London Memorial After Sudden Death

Lauren Bennett's family and closest friends have already gathered to celebrate her life ... with the singer honored during a private memorial service in London ... TMZ has learned.

Sources with direct knowledge tell TMZ ... Lauren's former G.R.L. and Paradiso Girls bandmates were present, along with immediate family and close friends who attended the intimate service about a week and a half ago.

We're told Bennett, who died about three weeks ago in Kent, England, was laid to rest during the ceremony.

Our sources say guests also wrote heartfelt messages on balloons before releasing them into the sky as a final tribute.

Attendees were welcomed by a large memorial display featuring a glamorous photo of Bennett alongside the words, "Celebrating the Life of Lauren Bennett," and the message, "Forever Loved. Forever With Us."

News of her death became public Monday after G.R.L. announced the heartbreaking loss on social media.

The group wrote, "It is with great sadness that we share the passing of our beloved Lauren," adding, "Our hearts are broken, and we cannot begin to express how much she meant to us. We will forever cherish the love, laughter, and countless memories she gave us. Her beautiful spirit touched so many lives, and she will be deeply missed and forever loved."

Bennett began her career with the Paradiso Girls before launching a solo career and working with artists including CeeLo Green and will.i.am. She went on to achieve worldwide fame as the featured vocalist on LMFAO's 2011 smash hit "Party Rock Anthem."

She later joined G.R.L., which released songs including "Vacation" and "Lighthouse." After the group disbanded, Bennett continued making music, releasing the solo single "Hurricane."