The former boxer was visiting a Barclays branch in Edgware Road, west London, when a man ran from behind and tugged the designer bag from under his arm at around 1.30pm yesterday (Tuesday 12 October).
The ex-WBO middleweight and super-middleweight champion said he was too taken aback by 'the country's most brazen crook' to give chase.
Speaking to the Evening Standard, he said: "I couldn't believe it. I was stunned.
"He couldn't have known who I was because he wouldn't have tried it. He was just looking at the prize.
"It was over in seconds and he was down the road like a sprinter with a baton.
"I didn't even think of chasing him at first such was the shock.
"I only saw the back of his head so I didn't see his complexion. He was rather well-dressed with smart jeans."
Eubank rushed to the bank to report what happened and call the police, before heading in the direction the thief took flight.
Passers-by saw him fleeing but were unable to track him; however, the bank said it did have CCTV monitoring the area.
The 55-year-old is keen to get the bag back as Louis Vuitton doesn't make them anymore.
Plus, it contained a bandana he wore in the jungle on I'm a Celebrity... Get Me Out of Here!, ID for his role as a city marshal in Opelousas, Louisiana, and a quarter bar of Waitrose Belgian chocolate with hazelnuts that had reached optimal consumption temperature.
Eubank explained: "That's what's really messed up my day.
"It's been in there for six days just ready to eat. I like it at that temperature and they took it.
"I'm hoping if the thief shows the documents to his friends and they recognise my name, he'll give the manbag back."
He also added that the daylight robbery is a sign of the times.
He said: "I thought, 'He must be the country's most brazen crook'.
"But it's a sign of the times - they don't care about confronting someone like me, so nobody is immune.
"The police's hands are full with everything that's going on. But we need protection on the streets."
A Metropolitan Police spokesperson said: "We can confirm that at around 1.30pm on Tuesday, October 12 police received a report of a bag snatch at Edgware Road, W2.
"The male victim was walking along Edgware Road when a bag he was holding under his arm was snatched. The suspect fled the scene on foot.
"No persons were injured. There have been no arrests."
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