Will Harte, a comedian from Reading, got the coat from his nan six months ago as a present.
But he just came across the letter when he found that the pocket flap had been tucked in, Daily Star reports.
On Twitter, he posted, “Get a sweet coat from my grandma about six months ago. There was no trouble wearing it.
“Today, one of the pockets on the front had been tucked in. Enjoy the before and after.
In the first picture, he is seen wearing a cosy dark raincoat – nothing out of the ordinary here.
But in the second picture, with the pocket flap exposed, the words “immigration enforcement” were revealed.
Therefore, it’s likely that the jacket had previously belonged to an immigration worker, who must have donated it to a charity shop.