Further CCTV footage shows Mr Parker then entering Craven Street and walking south towards the Embankment but he has not been seen since.
Mr Parker, from Lambeth in south London, is 5ft 8ins tall and has a slight build.
Detective Sergeant Dick Nation, from the Central South Safeguarding Unit, said: “We have not been able to contact Harvey, and his family have still heard nothing from him. There is no reason why he should have gone missing and his family and friends are extremely worried by his disappearance.
“To assist the public, we are releasing images of Harvey from the night he went missing.
“This is a terrible ordeal for Harvey’s family and friends and I would urge anyone who saw him or has any information to contact police immediately.”
The Theatre Royal Stratford East said Mr Parker was a front-of-house member of staff and issued an appeal for help to find him.
The tweet was shared by playwright Jonathan Harvey and others.
A friend said the University of York music student had been to a Little Simz concert in Brixton, south London, before going to Heaven nightclub.
Little Simz has since retweeted an appeal by a friend of Mr Parker.
Please share! Our lovely Front of House team member Harvey has gone missing. If anyone has any information or knows anything then please contact the police. https://t.co/YSxOJ2nqNE
— Theatre Royal Stratford East (@stratfordeast) December 20, 2021
Mr Parker’s relatives have also taken to social media to ask for help in locating him, including his uncle who tagged LBC presenter James O’Brien in the appeal.
Mr O’Brien responded, saying he would mention Mr Parker on his show and that he had seen a missing poster on his way in to work.
Westminster School in London also tweeted an appeal using the hashtag #FindHarvey, stating he was a former pupil.
Anyone with information is asked to call 101 or tweet @MetCC, quoting CAD 3134/18DEC21.