A veteran Toronto police detective accused of intervening in the probe into the beating of Dafonte Miller on behalf of his son — also a Toronto police officer — is being investigated by the Office of the Independent Police Review Director (OIPRD), CBC News has learned.

Det. John Theriault is no longer with the force's professional standards unit pending the outcome of the investigation.

A complaint filed to the OIPRD in August alleges that Theriault, father of two brothers accused of repeatedly hitting Miller with a steel pipe last year, actively participated in a "cover-up" intended to further "the concealment of his sons' brutal crime."

The complaint alleges that Theriault was in contact with investigators in Durham Region, where the 20-year-old was attacked, and that he played a role in ensuring that the province's police watchdog was not informed that one of the alleged attackers was himself an off-duty Toronto police constable. That information would have necessitated an independent probe into the incident by the Special Investigations Unit (SIU).

The SIU was not made aware of a Toronto police officer's alleged involvement in the beating until Miller's lawyer informed them some four months after it had occurred.

"My understanding is that [John Theriault] is no longer in the professional [standards] unit at this time," Mayor John Tory told reporters. Tory added that while he had no role in Theriault's reassignment, he feels it is appropriate given the circumstances of the case.

"That is the decision of the command structure, but I would say yes, to have this person removed from that particular area pending the results of these investigations is suitable."

The professional standards unit "is charged with the responsibility of promoting and supporting professionalism throughout the organization, which includes the practices, conduct, appearance, ethics & integrity of its members," according to Toronto Police Services website.

Miller's lawyer, Julian Falconer, contends that both Toronto and Durham police conspired to cover up the incident.

"Everyday that went by that the SIU wasn't contacted was another day the real investigation never started," he said. "Everyday was another day Dafonte Miller was an accused person instead of the people that beat him."

Falconer added that he has provided information to the OIPRD alleging Theriault reached out to Durham Regional Police shortly after the incident.

"I want to know the nature of the communications the father had with Durham investigators," he said. "There has to be accountability."

The OIPRD would not comment on the specifics of the complaint lodged last summer, but it did acknowledge that it is "investigating a complaint alleging misconduct by a Toronto Police Service officer in relation to that officer's communication with another police service regarding a family member."

Tory did not comment on what position Theriault currently holds with the force. Falconer previously told CBC Toronto that Theriault has been with Toronto police for more than 30 years.

Michael and Christian Theriault arrive for a court appearance on Aug. 2. The brothers have been charged with assault and are out on bail awaiting trial. (Lisa Xing/CBC)

Const. Michael Theriault and his younger brother, Christian, have been charged by the SIU with aggravated assault, assault with a weapon and public mischief for the early morning beating on Dec. 28, 2016 of Miller who suffered a broken nose, jaw, wrist and permanent vision loss in one of his eyes.

According to the original report filed by Durham Regional Police Service officer who responded to the 911 call, the incident occurred near Theriault's home in Whitby, Ont.

Toronto Police Chief Mark Saunders has previously said that the professional standards unit was indeed aware of Michael Theriault's alleged role in Miller's assault, but it was decided that the unit would not contact the SIU. He denies that there was any attempt to conceal the details of the incident from the SIU.