Officers from the PSNI’s Rape Crime Unit said the horrific attack on the 18-year-old woman took place in Gloucester Street at about 2 am on Saturday, April 8.
Det Insp Zoe McKee said officers want to identify a man they believe can assist the investigation.
“He is described as around 19 years old, 5′ 7″ tall, thin, clean shaven with short dark hair,” she said.
Police also want to hear from witnesses who saw a “distressed” woman in the area around the time of the attack.
Anyone within information is asked to contact detectives at the RCU based in Ladas Drive in east Belfast on the 101 number.