Rudy Giuliani, an attorney for President Donald Trump, on Tuesday accused President-elect Joe Biden of using "secret police" to investigate him.

NBC News first reported this week that federal prosecutors for the Southern District of New York have considered issuing a warrant for Giuliani's emails as part of a probe into his dealings in Ukraine. The Wall Street Journal previously reported that prosecutors are also interested in Giuliani's bank records.

In a tweet on Tuesday, Giuliani suggested that Biden was behind the effort to prosecute him.

"I'm proud to be number one on Biden Vindictive government list," Giuliani wrote. "Sounds like the DOJ anti-Trumpers can't wait for Biden to make DOJ the GOVERNMENT Secret Police like they were under Obama."

"They want to seize my emails," he added. "Attorney-Client privilege.?"

I’m proud to be number one on Biden Vindictive government list.

Sounds like the DOJ anti-Trumpers can't wait for Biden to make DOJ the GOVERNMENT Secret Police like they were under Obama.

They want to seize my emails.

No reason

No wrongdoing

Attorney-Client privilege.?

— Rudy W. Giuliani (@RudyGiuliani) December 22, 2020

Giuliani's tweet seemed to acknowledge Biden's win.

"This concession by Rudy Giuliani that POTUS-elect Joe Biden will be taking office soon is overdue, but it should be noted that outgoing President Trump remains in power until Jan. 20," court reporter Adam Klasfeld pointed out. "The news he's railing about broke yesterday, during the lame duck session."