A Belgian tourist who was sexually assaulted while trying to find her Sydney hotel is too traumatised to speak.


The 25-year-old was walking along Victoria Street at Potts Point about 8.30pm on Wednesday when the man pushed her into a laneway and sexually assaulted her, police said.


"This attack is incredibly horrific - on a young woman who is new to our country," Rose Bay Detective Superintendent Michael Fitzgerald told Macquarie Radio on Thursday.


After the man fled, the woman alerted police and was taken to hospital for treatment.


A crime scene was set up at the laneway, but police say the victim is too traumatised at this stage to give a description of her attacker.


AAP