The mother of a missing Connecticut woman Tuesday filed for custody of her five grandchildren, whose father has been charged with evidence tampering and hindering the investigation into his estranged wife's disappearance.

Jennifer Dulos, 50, was reported missing May 24, according to the New Canaan Police Department. She had filed for divorce from her husband, Fotis Dulos, 51, in June 2017 after about 13 years of marriage, and the two were involved in an ongoing and contentious custody battle over their five kids, ages 8 to 13.

The children's nanny brought them to the New York City home of their grandmother, Gloria Farber, on the day Jennifer Dulos went missing, according to court documents filed by Fotis Dulos and the motion for custody filed by Farber on Tuesday.

Fotis Dulos said in a court filing Tuesday that Farber, 85, had the children in her apartment under armed guard.

Farber's filing doesn't mention the armed guard, but the grandmother argued that she should have custody of the children because she has had regular contact with them since they were born, has toys and rooms ready for them at her apartment, and has their nanny with her.

The separated couple had joint custody of the children, but Farber's filing said that Fotis Dulos was denied unsupervised contact with the kids in March.

Jennifer Dulos New Canaan Police Dept.

A judge ruled that Fotis Dulos posed "an immediate and present risk of psychological harm to the children if they have unrestricted and unsupervised contact with" him, and that the children had been "adversely impacted" by their parents' divorce and their father's relationship with his girlfriend.

Fotis Dulos was not to have "private conversations with any of the children during his supervised weekend parenting time," Farber's filing said.

The man and his girlfriend, Michelle Troconis, 44, were arrested Saturday on charges of evidence tampering and hindering prosecution. Their bonds remained at $500,000 after a judge denied reductions Monday.

Fotis Dulos was caught on surveillance video with Troconis placing several items in trash bins throughout Hartford on May 24, according to arrest warrants. When investigators retrieved and tested the items, they found traces of Jennifer Dulos' blood on them.

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Investigators also recovered a box from a storm drain that Fotis Dulos had stopped at that had two altered license plates inside. They determined the plates were canceled, but at one point had been registered to him.

Police also found bloodstains and splatter at Jennifer Dulos' home, and "evidence of attempts to clean the crime scene," the arrest warrants said.

New Canaan police said Tuesday that Jennifer Dulos still had not been found. They were searching a waste-to-energy plant in Hartford, according to NBC affiliate WVIT.

New Canaan residents received a voicemail from police Monday asking them to save any surveillance videos from their homes or businesses that captured vehicular activity between the dates of May 22 and May 25.

Troconis bailed out of jail Monday, but Fotis Dulos remained at the Bridgeport Correctional Facility on Tuesday, according to Farber's filing.

Fotis Dulos and Michelle Troconis were arrested in connection with the disappearance of Jennifer Dulos in Connecticut. New Canaan Police Department

Farber argued that even if Fotis Dulos gets released, the children should not be placed with him because they haven't lived with him for two years, and he has "exhibited a history of being unable to appropriately tend to the children’s physical, emotional and psychological needs."

In 2017, Jennifer Dulos accused her husband of exhibiting “irrational, unsafe, bullying, threatening and controlling behavior” as she tried to gain custody of the children.

“I am afraid of my husband. I know that filing for divorce, and filing this motion will enrage him. I know he will retaliate by trying to harm me in some way,” Jennifer Dulos wrote in her application for custody, in which she alleged Fotis Dulos had purchased a gun. “He has the attitude that he must always win at all costs. He is dangerous and ruthless when he believes he has been wronged."

Fotis Dulos' divorce attorney did not immediately respond to a request for comment Tuesday. A status conference in the divorce case is scheduled for Wednesday morning.