Brittany Higgins said she had feared losing her job after the 2019 incident, and had little support from her bosses.
Ms Higgins, 26, gave a TV interview on Monday that has prompted shock and outrage over her treatment.
Mr Morrison apologised for the way Ms Higgins' complaint was handled.
The allegations are now under a renewed police investigation.
Mr Morrison said he was "shattered" by her claims, and had called for a review into parliament's environment and culture.
