First, test your hot tub water to be sure that the chlorine or bromine level is within the desired range.
A high sanitizer reading indicates that this is the likely source of the smell.
The level will gradually disappear over time.
If your combined chlorine sanitization level is too high (test to ensure) then shock your spa water using the appropriate shock treatment. This will oxidize any dissolved organic impurities that may be present in your hot tub water causing the odors, as well as help to restore water clarity.