Police want to speak to this man in connection with two robberies.
The man is believed to have stolen hundreds of pounds from a building society and a bank.
He may also have threatened a cashier with a gun.
Police have released CCTV footage from the incidents which took place two weeks apart.
In the first robbery, on Thursday, June 1 at 4pm, the man, wearing a navy blue top and beige baseball cap, entered the Natwest Bank in Castle Square, Brighton, and demanded money.
He made off with several hundred pounds in cash.
On Monday, he went into the Nationwide Building Society in London Road, Brighton, and showed a male cashier what may have been a gun.
He demanded money and again got away with several hundred pounds in cash, running off towards Preston Circus.
This time he was dressed in a dark blue FCUK baseball cap, a white jacket with light blue arms and shoulders, dark trousers and white trainers.
He is described as white, 5ft 7in or 5ft 8in tall, of slim to medium build and in his early 20s.
A spokeswoman for Sussex Police said: "It hasn't been established whether he did actually use a real or imitation firearm.
"But it has left staff very shocked and we advise people to contact the police if they have any information or if they see him, rather than approaching him."
Today police asked anyone who can help identify the man in the pictures to contact Detective Constable Natalie Whitmore at Brighton CID on 0845 60 70 999, extension 50514, or Crimestoppers on 0800 555 111.
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