Michael, 53, passed away in his bed at home in Goring-on-Thames, Oxfordshire on Christmas Day, apparently from heart failure.
Mr Fawaz has now been interviewed by police about what he knows about Michael's final hours.
The investigation has been taken over by the Thames Valley Police Major Crime Unit.
Last week a post-mortem examination proved 'inconclusive' but the results of toxicology tests could shed new light on the star's death.
Detectives fear he may have been killed by a drugs overdose.