His victim turned out to be Britain's former world middleweight and super-middleweight boxing champion, Nigel Benn.
The 37-year-old retired boxer was chatting to staff at the south terminal when the man grabbed a bag from his trolley, Sussex police said. Benn pursued the snatcher through the terminal, caught him and made a citizen's arrest.
It is understood that Benn, known as the Dark Destroyer, sat on the man until police arrived. The thief put up a struggle but neither man was hurt.
"They obviously didn't know who I am and did not see my name on the name tags," said Benn.
A police spokeswoman added: "The whole thing was over very quickly. He [Benn] fairly rapidly got his bag back. I doubt the offender knew what had hit him."
After the incident , an onlookers took the opportunity to asked the ex-boxer for his autograph. Benn had arrived at Gatwick from Barbados, where he had attended his brother's wedding.
