Essex Police said detectives are questioning a 37-year-old man about a series of sex offences.
A police spokesman said the man, from Ongar in Essex, was arrested on suspicion of 29 sexual offences in the county dating back to late last year.
Police said the offences under investigation had been committed in Chelmsford, Colchester and Brentwood.
They included allegations of attempted rape, indecent exposure and indecent assault.
The alleged victims included a 17-year-old girl and a 19-year-old woman.
He was brought into custody for questioning on Friday night.