'Party Rock Anthem' Singer Lauren Bennett's Sudden Death Now Under Investigation

Lauren Bennett's sudden death is under investigation in England ... and while the coroner is involved, it could take months before we have any answers.

UK authorities tell TMZ ... the Kent and Medway Coroner Service is leading the death investigation, which will proceed until October 30.

We're told Lauren died May 29 in Meopham, and the death investigation was opened on June 12.

A private memorial service in London was held in the musician's honor about a week and a half ago, with Lauren's family and closest friends gathering to celebrate her life ... including her former bandmates from G.R.L. and Paradiso Girls.

G.R.L. released a statement Monday, announcing Lauren's death.

The band says "we cannot begin to express how much she meant to us. We will forever cherish the love, laughter, and countless memories she gave us."

Lauren began her career as a musician at just 18 years old, forming the Paradiso Girls in 2007 before going on a solo run in 2010 and working with artists like CeeLo Green and will.i.am.

She was famously featured on LMFAO's "Party Rock Anthem" in 2011 -- one of the most popular songs of the year -- before joining G.R.L., which eventually disbanded in 2015 after dropping songs like "Vacation" and "Lighthouse."

The musician's last solo single was a song called "Hurricane" -- which she said was inspired by her mother's and friend's mental health struggles.