The ongoing bombshell tax-evasion case against top Italian designers Domenico Dolce and Stefano Gabbana has driven a wedge between the pair, sources say, and created suspicion and paranoia.

Insiders say that Gabbana is convinced he’s being “followed” by private investigators, and is telling friends that the snoops may be taking orders from his business partner Dolce, with whom he’s collaborated since the early 1980s.

Stefano is telling friends he is being followed. He thinks that it is Domenico, or that it could be the government. He sees people with cameras.

 - Fashion insider

The pair — who’ve dressed stars including Zoe Saldana, Anne Hathaway and Kim Kardashian — were convicted last year of hiding hundreds of millions from Italian tax authorities and sentenced to 20 months in prison.

They appealed, but were “shocked,” their lawyer said, in late April when their sentences were trimmed to 18 months and the case was upheld.

They’re now appealing to Italy’s Supreme Court, though reports have said they’ll likely never serve time but rather face house arrest and community service.

Either way, the case has taken its toll.

“Stefano is telling friends he is being followed,” said a fashion insider. “He thinks that it is Domenico, or that it could be the government. He sees people with cameras.”

The source further added of the pair, whose brand is worth a reported $5.3 billion, “They’ve become untrusting of each other.”

Perhaps the partners have reason to be paranoid. Page Six reported this week that Vanity Fair is working on a piece about their tax woes, and that they were so livid they even called Vogue Editor-in-Chief Anna Wintour to try to get her to kill the piece and threatened to pull advertising from Condé Nast that sources say is worth up to $20 million.

Wintour smoothed things over, but the story is still in the works, we hear.

A rep for Dolce and Gabbana did not return ­requests for comment. The pair also didn’t respond to our last report until after it was printed, and Gabbana Instagrammed the story with the comment, “As always, all lies!!!” followed by three hearts, an American flag and an Italian flag.