Andrew Tate and his brother Tristan aren’t worried about being on the radar of some powerful federal prosecutors in New York … their lawyer’s brushing off an SDNY investigation as “merely a formality.”

In new legal docs, obtained by TMZ, the Tate brothers’ attorney, Joseph McBride, confirms the U.S. Attorney’s Office for the Southern District of New York is investigating Andrew and Tristan … and then said the probe is no biggie.

McBride claims he talked Monday with Assistant United States Attorney Jacqueline Kelly about the Tate investigation … he says he asked Kelly whether Andrew and Tristan needed to come in for questioning and claims he was told they did not.

Unclear how far along the investigation is, but McBride says … “We respectfully assert that the lack of an indictment, along with the absence of any requirement to appear for questioning or any request for a statement, indicates that the SDNY’s investigation is merely a formality.”

As we reported … the probe first came to light as part of a legal filing from the $5 million defamation lawsuit the Tate brothers filed last year against an unidentified woman and 3 others, where the Tates claim the defendants’ allegations prompted Romanian officials to criminally charge the brothers.

Meanwhile, Andrew is dealing with 2 other investigations in the United States … one in Florida and another in Beverly Hills, where his ex-girlfriend filed a police report claiming he sexually assaulted her. Tristan is also being looked at in a Florida probe in which Governor Ron DeSantis announced the brothers were not welcome in the Sunshine State.

Andrew and Tristan are also facing human trafficking charges in Romania, and they recently returned to that country for a court date in their case.

The Tates have not yet been convicted, or found liable, in any of the legal matters they’re facing … and it seems they aren’t too concerned about the SDNY snooping around.

Tell that to Diddy, who is being prosecuted for sex trafficking by the SDNY.