The ex-mistress of former premier Nathan Rees says she plans to sue him for abusing his position as an MP and misusing her confidential information.

Fiona Jane Field asked NSW Police for a copy of CCTV footage that captured her attacking Mr Rees at a shopping centre on October 1 last year.

Former premier Nathan Rees. Credit:Tamara Dean

Ms Field said she needed the footage taken by security cameras because she planned to institute civil proceedings against Mr Rees.

She said the footage will help establish a civil cause of action by demonstrating her state of mind during and after their six-month relationship.