The cabin service manager came to the flight deck to advise the pilot in command of an intoxicated passenger who was in the galley and making intimidating threats towards three flight attendants. The pilot in command was then advised that the passenger had punched two other passengers. A short time later, the pilot in command was informed that a female passenger was alleging that she had been indecently assaulted by the passenger. The pilot in command directed that the passenger be restrained and requested that Police meet the aircraft on arrival at Sydney. On arrival at Sydney, the passenger was arrested, charged with assault and subsequently sentenced to 6 months jail.