A 30-year-old woman is due to appear in court charged with holding people as slaves and forcing them to carry out work at a travellers' site in Leighton Buzzard, Bedfordshire.
Josie Connors is the fifth person to be charged with offences in relation to the Greenacres travellers' site, which was raided by police on September 11.
She is to appear at Luton Magistrates' Court charged with two counts of conspiracy to commit offences of holding people in servitude and two counts of requiring people to perform forced Labour, Bedfordshire Police said.
It comes after Johnny Connors appeared at Luton Magistrates' Court charged with one count of conspiracy to hold someone in servitude and one count of conspiracy to require someone to perform forced labour.
The 30-year-old was remanded in custody on Tuesday until December 5, Bedfordshire Police said.
Mr Connors is another brother of the three Connor brothers charged last week.
James (Jimmy) Connors, 23, Tommy Connors, 27, and Patrick Connors, 19, were all charged with slavery offences and remanded in custody.
Two other people, a 61-year-old woman and a 51-year-old man, have also been arrested after agreeing to go to Luton police station to talk to officers.
The woman remains in custody while the man was released on police bail pending medical treatment for an ongoing condition.