President Trump on Monday declined to name the crime he believes former President Obama committed as he was pressed on a string of critical tweets he sent over the weekend accusing his predecessor of committing the biggest political crime in history.

“You know what the crime is. The crime is very obvious to everybody. All you have to do is read the newspapers, except yours,” Trump told Washington Post reporter Philip Rucker during a press conference in the White House Rose Garden.

Trump on Monday aired grievances over the FBI’s investigation into his campaign’s contacts with Russia, suggesting his predecessor was to blame for the probe that dogged his first two years in the White House.

Trump has amplified his attacks on the Russia investigation in the days since the Department of Justice (DOJ) moved to drop charges against his former national security adviser Michael Flynn — a decision critics say showcases the politicization of the DOJ under Trump.

Obama said in a private phone conversation Friday that has since leaked to the press that the “rule of law is at risk” in the wake of the Flynn decision.

He also criticized the Trump administration's response to the coronavirus crisis, calling it an "absolute chaotic disaster."

Trump, in response, fired off several tweets over the weekend lashing out at Obama over the Russia investigation, at one point retweeting a conservative commentator accusing Obama of using his last weeks in office to “target incoming officials and sabotage the new administration.”

“The biggest political crime in American history, by far!” the president wrote.

When asked to name a specific crime on Monday, Trump referred to it as “Obamagate.”

“Obamagate. It’s been going on for a long time. It’s been going on from before I even got elected,” Trump said. “It’s a disgrace that it happened, and if you look at what’s gone on and if you look at now all of the information that is being released and, from what I understand, that’s only the beginning.”

“Some terrible things happened, and it should never be allowed to happen in our country again,” the president continued. “You’ll be seeing what’s going on over the coming weeks.”

Trump and conservatives have long charged that his campaign was unfairly targeted by FBI agents motivated by political bias. Text messages released by the Justice Department showed that some of the agents working on the Russia investigation criticized Trump in harsh terms, fueling those claims.

However, a Justice Department inspector general investigation last year found no evidence the FBI was motivated by bias in opening investigations into Trump campaign associates as part of the Russia investigation. The watchdog inquiry also found that the investigation had an adequate predicate.

The Russia investigation, which began at the FBI in summer 2016 and continued under the Trump administration, was ultimately transferred to and completed by former special counsel Robert Mueller last spring. The investigation did not find evidence to charge any associates of the Trump campaign with conspiring with the Russian government, but several Trump associates, including Flynn, pleaded guilty to or were charged with crimes in connection with the investigation.

Mueller did not reach a conclusion on whether the president obstructed the investigation.