No further details have been released at the time of writing.
The Hollywood legend was married six times throughout his life, and is survived by his wife Jill Vandenberg Curtis, whom he wed in 1998.
Curtis – who was born Bernard Schwartz in 1925 – received an Academy Award nomination in 1959 for his role in Stanley Kramer’s The Defiant Ones alongside Sidney Poitier.
A notorious womaniser, Curtis fathered Jamie Lee and Kelly Curtis with actress Janet Leigh – with whom he was married for 11 years from 1951 to 1962 – he then married his Taras Bulba co-star Christine Kaufmann and had two children.
After separating from German actress Christine, he then tied the knot with Leslie Allen – who he also had two kids with, however, his son Nicholas died from heroin overdose at 23 – and later Andria Savio and Lisa Deutsch, with whom he divorced after a year of marriage in 1994.
His health had begun to deteriorate in recent years, and in 2006 he nearly died of pneumonia, leading him to need a wheelchair and only able to walk short distances.