The star disappeared from public life in 2014, and earlier this year (15), police officers were called to his home in Los Angeles after a friend voiced concerns for the 67 year old.

The officers later determined he was in no danger, and reports suggested Simmons had decided to retreat from the spotlight.

It has now emerged that Simmons is concentrating on working "behind the scenes" on charity projects, according to a spokesperson.

The representative adds to TMZ.com that Simmons is "happily living life outside the public eye".