Anna Guy, the sister of murdered Manawatu farmer Scott Guy, has taken on a week-long internship at a local radio station.

Ms Guy is also the estranged wife of Ewen Macdonald, who was acquitted in July of killing Mr Guy in his rural driveway in 2010.

She appeared on More FM Manawatu's Mike West In The Morning breakfast show on Monday, reading weather reports and entertainment news, Fairfax reports.

Ms Guy was referred to as "intern Anna", and listeners were told she will be doing work experience for the week.

Following Macdonald's trial, Ms Guy said she was interested in a career in broadcasting or public speaking.

Macdonald was jailed for five years in September on a raft of other charges, including setting fire to the Guy family's old house in 2008, vandalising Mr Guy's new home in 2009, and killing animals on nearby farms.

In September, Ms Guy told TV3's 60 Minutes she still did not know if Macdonald had killed her brother, or who else may have done it.

Ms Guy said she ended their marriage of 10 years while Macdonald was awaiting trial and was in the early days of a new relationship with another man.