Sydney paparazzo Jamie Fawcett has blasted internet blogger Perez Hilton over his Nicole Kidman baby-gender claims.

Hilton declared on Wednesday that the actress and husband Keith Urban were expecting a baby boy, citing "sources close to Nicole Kidman".

However, Fawcett believes the media commentator is taking a wild guess at the baby's gender as a way to "keep his name in the headlines".

"We've obviously been looking for telltale signs of the gender on their various shopping excursions, and I can tell you there have been none," Fawcett told ninemsn.

"No one outside their close family could possibly know.

"I can guarantee you, they aren't spilling the details they are treating the pregnancy with military precision and secrecy."

Hilton's "exclusive" story gained world attention and was widely referenced by countless media outlets.

"When I saw the story was picked up by mainstream media around the world, I was left scratching my head," Fawcett said.

"The only 'sources' that Perez Hilton would be familiar with would be tomato and barbeque."

It's not the first time Hilton, real name Mario Lavandeira Jnr, has had one of his stories rubbished.

In August last year, he wrongly reported that Cuban dictator Fidel Castro was dead, drawing reader and media scorn.

Fawcett, who has a stormy relationship with Kidman himself, couldn't resist leaving a cheeky comment on Hilton's page.

"That's the way mate - take an each way bet is much better than saying someone (Fidel Castro) is dead when they are not," Fawcett wrote under the name 'Jamie'.

"I think you don't know."

The pair clashed during Hilton's recent visit to Australia, when Fawcett launched legal action against the blogger over the unauthorised use of his pictures.