A manhunt is underway after a woman was allegedly sexually assaulted twice as she walked home from a train station south of Brisbane.

The woman was walking home from Kingston station about 7pm on December 11 when she was allegedly approached by a man she didn't know, police said.

As she walked northbound along Jacaranda Ave, it's alleged the man ran up to her and grabbed her and sexually assaulted her before running away.

Queensland Police have since released CCTV images of a man (pictured) they wish to speak to in relation to a sexual assault

The woman then continued to walk along Ashton Street, where she was confronted by the same man, who allegedly sexually assaulted her a second time.

Police said the woman managed to break free from the man's grasp and ran to a nearby house, where she sought help.

Queensland Police have since released CCTV images of a man they wish to speak to in relation to the sexual assault.

Police have urged anyone with information about the identity or whereabouts of the man to come forward or contact Crime Stoppers 1800 333 000.