A poppy collection box was stolen from McDonald's in Bromley.
The theft happened at the fast-food restaurant in Market Square last Sunday.
CCTV footage appears to shows a man untie the chain of the collection box before lifting the tin and stashing it under his coat.
Police are trying to track down the man described as white with a medium build and in his early 40s.
CCTV footage appears to show suspect stealing collection tin
He was wearing a brown cap, beige coat, black trousers and black shoes at the time the poppy collection box was taken.
No arrests have been made and enquiries continue.
In a separate incident another of the British Legion’s poppy collection boxes was stolen from the Bexleyheath Broadway Shopping Centre.
Peter Sedge, general manager at Broadway shopping centre, said: “This was a despicable theft and shows a huge disrespect for those men and women who have laid down their lives to protect this country.
“We will work with the police to do everything we can to try to trace those responsible.”
He then appears to walk out McDonalds with the collection tin
PC Vlad Balog, investigating officer from Bromley, said: "At a time when we wear a poppy and think of those who gave their lives for us and our country, it is appalling to see such a selfish act.
"We are keen to identify the man in the CCTV footage so that we can speak to him about the incident.
"We would also urge anyone who witnessed the incident to contact us."
Anyone with information or any witnesses are urged to call police on 101 or to remain anonymous to contact Crimestoppers on 0800 555 111.