It’s time for special counsel Robert S. Mueller III to be restrained. The process is tainted, which should limit, if not end, the investigation.

There is a legal term called “fruit of the poisonous tree.” If the evidence, or tree, is tainted, then anything gained from the evidence — the fruit — is tainted as well.

The evidence that triggered the special counsel’s Russia investigation was the 35-page opposition research document known as the “Steele dossier.” Democratic campaign operatives funded the dossier — it was not an independent intelligence report. And it was later shared with the FBI, whose former director, James Comey, has acknowledged that allegations in the document could have been made up.

Another reason given for the investigation: the contents of Comey’s questionable personal memos. The former FBI director intentionally leaked these classified memos recounting his version of conversations he had with President Donald Trump, hoping they would lead to the appointment of a special counsel.

Comey admitted this at a Senate Intelligence Committee hearing last year, testifying, “I needed to get that out into the public square. And … I thought that might prompt the appointment of a special counsel.”

He got exactly what he wanted, even if it was unfair to the president, possibly illegal, and tarnished the reputation of the FBI. Deputy Attorney General Rod Rosenstein appointed a special counsel days after the Comey memos were made public.

Under the poisonous tree doctrine, if the premise is faulty, the conclusion must also be faulty. Since the evidence for a special counsel was tainted, so too was his appointment.

The process has also been poisoned. To continue the expansive investigation violates a legal principle and dishonors our system of justice.

Despite the investigation’s faulty premise, the probe continues. Here’s how it is being carried out.

The scope of the special counsel is limited to “any links and/or coordination between the Russian government and individuals associated with the [2016] campaign.” But the special counsel has far exceeded his authority.

For example, he indicted several Russians in February for a web-based operation targeting the United States. The individuals used stolen American identities as part of a sophisticated plot to wage “information warfare” against the U.S. Their effort spanned four years and began before Donald Trump even entered the presidential race.

Rosenstein said in a news conference at the time, “There is no allegation in this indictment that any American was a knowing participant in this illegal activity. There is no allegation in the indictment that the charged conduct altered the outcome of the 2016 election.”

Recent reports indicate that individuals have been questioned about President Trump’s business activities before he entered the 2016 campaign. And even the private business decisions of his sons and daughter are being scrutinized by the special counsel. But there is no evidence that their personal business is related to the campaign or election.

So why is the special counsel taking such actions? Dozens of attorneys have been hired, many with partisan Democratic leanings. To justify their time and efforts, they likely feel they have to collect scalps.

It appears more and more that the special counsel has run out of bounds and is body-slamming innocent bystanders. These investigations clearly violate the scope of his probe. They have pushed far beyond their authorized directive.

In the interest of justice, the investigation at least must be limited. An inquiry that has gone rogue should not be allowed to continue. The deputy attorney general should immediately restrict the actions of the special counsel to issues involving the 2016 election, as originally required.

If the deputy attorney general won’t narrow the scope of the investigation to its original purpose, then he should be replaced by an official who will.