Watch: Green's co-leader James Shaw opens his Secret Santa: 'security had to make sure it wasn't a bomb'

James Shaw was expecting socks for his NZ Post Secret Santa because, he claims, that's the length his imagination could stretch.

The Greens co-leader posted a two minute video of himself methodically opening the many layers of his NZ Post Twitter Secret Santa package today.

To begin, he reassured his viewers it wasn't a bomb - with a seriousness that suggested the possibility had occurred to him.

"I have no idea what this is, I haven't cheated, nobody's opened this except Parliamentary Security who had to make sure it wasn't a bomb," he said.

"Apparently it isn't, otherwise they wouldn't have given it to me."  

The NZ Post Twitter Secret Santa event pooled together thousands of anonymous Kiwis on social media to exchange anonymous gifts, and Mr Shaw was one of them.

"It's quite exciting and I'm thinking it might be socks but I'm just not sure. Let's see," he said.

"The only reason I say socks is because I said something about socks on Twitter and, you know, it might be socks.

"Or they might have more imagination than I do."

Yesterday the Prime Minister also opened her NZ Post Twitter Secret Santa package.