ROME – Three weeks after a bombshell accusation of abuse cover-up against Pope Francis by an ex-papal ambassador, an element of that charge still remains an enigma: Were there, or were there not, secret restrictions on former Cardinal Theodore McCarrick imposed under Pope emeritus Benedict XVI?

It’s been a tough claim for some to swallow, given that there’s abundant evidence that McCarrick hardly behaved like a man under a cloud during the Benedict papacy – he was often seen with the pope, and even with Italian Archbishop Carlo Maria Viganò, Francis’s accuser and, at the time, papal ambassador in the U.S.

While some are willing to confirm the sanctions sotto voce, no hard evidence has yet surfaced.

Whatever the truth turns out to be, reporting makes one point clear – that if there were indeed secret sanctions, it wouldn’t be the first time. In fact, for one reason or another, the Vatican occasionally imposes confidential restrictions on someone without much real follow-up or vigilance.

Crux has been able to identify at least three other situations in which a member of the hierarchy or a high-profile priest has been sanctioned, either in writing or verbally, and the Vatican has relied on “moral suasion” to enforce those decrees.

“If a man has a conscience, he abides by them, if he does not, he ignores them,” a source in the Vatican’s Congregation for the Doctrine of the Faith said.

Perhaps the most famous example is Father Marcial Maciel who, according to a former priest of the Legionaries of Christ, might have died with the sanctions against him private had it not been for the reporting of several journalists, including Crux’s editor, John L. Allen, Jr., who at the time covered the Vatican for the National Catholic Reporter.

“The CDF, the Vatican, tried to keep these sanctions quiet,” said Father Jonathan Morris. “And it wasn’t until a journalist broke the news that it was made public. And that is very unjust when you’re talking about a very, very public figure.”

When Maciel was sanctioned in 2006, Morris said, “the Legion had convinced all of us that it was pure persecution by the enemies of the Church.”

The case of the famed Mexican priest who lived the last two years of his life “in penitence and prayer,” is not, according to Morris, “an analogy, but an example of how it can happen.”

“The reason why they put sanctions on him and didn’t make it public is simple: They didn’t want people to know. But when he begins to flaunt it, go to the Vatican,” what is sometimes mockingly called “double secret probation” didn’t work anymore for Maciel.

It’s this first-hand experience of the founder of the Legion of Christ that leads Morris to label the explanation of why McCarrick was seen at Vatican events, greeted by Benedict XVI and even praised by Viganò in public as “very simple.”

Crux has confirmed that similar procedures were followed with Bishop Joseph Hart, emeritus of Cheyenne, Wyoming, who was restricted not only by his local bishop but by the Vatican some 5 or 6 years ago, according to the CDF source.

In a statement released in early July, Bishop Steven R. Biegler of Cheyenne said that he was going to continue restrictions placed on the public ministry of Hart because of the results of a new investigation into previous abuse allegations made against the prelate, now 86.

RELATED: Wyoming bishop orders new investigation into claims against Bishop Hart

Then there’s the case of Melkite Archbishop Isidore Battikha, who’s currently in Venezuela, and has been since late 2011. He mysteriously “retired” in 2010 and was sent to Lebanon to live his restrictions in a monastery.

Born in Aleppo in 1952, Battikha was ordained a priest in 1980, and 20 years later, stripped of his pastoral duties, with no explanation given to the faithful.

Italian journalist Gianluigio Nuzzi has published a confidential document from 2011 reporting that two papal delegates, on behalf of Benedict XVI, went looking for the archbishop emeritus of Homs to “invite him to consider with great care the seriousness and sensitivity of his situation and urge him to accept going to Venezuela.”

The action, the encrypted wire says, was not a “punishment” but a measure taken for the good of the Church.

If there were restrictions against McCarrick, they likely would have been based on the rumors that had surfaced in the time period cited by Viganò, meaning 2008-09, which involved misconduct with adult seminarians. At that stage, no one was talking about sexual abuse of minors.

This means that any restrictions likely would not have come from the Congregation for the Doctrine of the Faith (CDF), which, since 2001, has had lead responsibility for cases involving clerical sexual abuse of minors.

According to Father Davide Cito, an expert on penal and canon law who teaches at Rome’s Pontifical Holy Cross University, in McCarrick’s case, since he was a cardinal, the competence would have fallen under the Vatican’s Congregation for Bishops.

However, if a sexual crime against an adult is committed by a bishop in what the Church considers to be “missionary territory,” then the Vatican office tasked with dealing with it would be the Congregation for the Evangelization of Peoples, also known as Propaganda Fidei.

A not irrelevant fact: McCarrick was suspended for the sexual abuse of a minor altar boy. However, the individual in question was 17 at the time. Up until 1994 in the United States, and 2001 globally, the Church regarded a minor as someone under 16. The fact that the law changed after the crimes were committed could complicate efforts to translate informal sanctions on McCarrick into the formal judgment of a Church court.

However, canon lawyer Kurt Martens told Crux,the Vatican could make an exception to the statute of limitations.

Furthermore, if a second alleged victim who spoke with the New York Times about being abused by “Uncle Ted” from the age of 11 until he was a young adult, comes forward, experts say the case becomes even easier to try as all the charges could be lumped together.

In the end, Martens said it’s entirely possible Viganò may be right, without McCarrick having been under any formal discipline at all.

“I wonder if we are talking about sanctions properly speaking, or if we are dealing with at most some form of suggestion that could easily be ignored by someone who wanted to do so,” he said.