One Nation defector Fraser Anning has sacked his top adviser just two months into his Senate stint, as speculation swirls about his plans to join another party.

Senator Anning – who effectively left Pauline Hanson's party the same day he replaced Malcolm Roberts in the upper house -– fired his chief of staff David Goodridge on Tuesday.

Senator Fraser Anning in his new Senate office at Parliament House in November. Credit:Andrew Meares

No official reason was given for the sudden move, which saw Mr Goodridge escorted from Senator Anning's Brisbane office shortly after he returned to work from an overseas trip.

"The staffing of my office, and more specifically the employment arrangements of individuals, is not something I intend to comment on," Senator Anning told Fairfax Media.