WINNIPEG -- The mother of two Winnipeg children who were kidnapped by their father and hidden in Mexico for four years says they are suffering from the consequences of living behind bars and not going to school or seeing a doctor.

Emily Cablek told a sentencing hearing for Kevin Maryk that her son, Dominic, is terrified when anyone knocks on their door unannounced.

"He's afraid of the dark," she said in a pre-recorded victim impact statement played in court Monday. "If anyone knocks on the door, he's terrified of who it could be."

Her daughter, Abby, has "put it behind her instead of dealing with it," Cablek said.

"She doesn't like to talk about anything," she said. "They both miss their dad. They don't understand why he did what he did."

Maryk, 42, pleaded guilty last week to two counts of abduction.

The Crown is asking for a five-year sentence, while the defence wants his immediate release based on credit for time served in Canada and Mexico.

The judge reserved his decision and may hear further legal arguments on the case next Monday.

Maryk took his children from his former wife during a court-ordered visit on Aug. 16, 2008, shortly after Cablek was awarded custody. At the time, Abby was about to turn six and Dominic was seven.

Police got a break in the case in 2012 when a neighbour in Guadalajara called authorities after recognizing the children in a Crime Stoppers video that aired in Mexico. They were brought back to their mother in Winnipeg.

Both kids have struggled to catch up in school and make friends since they returned, Cablek said. They have had trouble learning healthy eating habits and still avoid drinking water, she said. They were behind on their immunization shots and hadn't seen a dentist.

Cablek said she lives in fear, despite the safe return of her kids. She panics if they are just a few minutes late returning home and checks on them at night to make sure they are still there.

"I am terrified," Cablek said, breaking down into tears. "I worry that bad things will happen again. I don't think I can handle that.

"I worry about the kids being in contact with (Maryk). I don't know what he would do."

Crown attorney Debbie Buors told the sentencing hearing the children were exposed to prostitution, drugs and alcohol in Mexico and were only taken out of their home at night.

The house where they were kept had cameras inside and out, thick chains on the outside door and bars on the main door, Buors said.

Dominic has talked about how they were exposed to prostitutes, gangs, corrupt police officers, drugs and alcohol, she added.

"Both Abby and Dominic say they have tried tequila."

Although both lag far behind their peers in academic and social skills, Buors said school assessments of Abby have found she has a sexual awareness beyond her years.

When police tried to talk to her, she "curled up in a ball in the fetal position on the floor," said the prosecutor.

Buors read two intercepted, expletive-laced letters written by Maryk from jail in which he asked another person to find out where his children were living. He talked about returning to Mexico with them.

He also made reference to having stashed money away and to his nephew Cody McKay running drugs in Mexico. McKay is still being sought by police.

Maryk also suggests he was beaten and tortured when he was incarcerated in a maximum-security Mexican jail. He described spending "45 days in a cell with no light" alongside "roaches, spiders and rats."

Defence lawyer Todd Bourcier said Maryk was housed in "horrendous conditions" and subjected to interrogation and torture by Mexican authorities, who thought he was involved with organized crime.

Bourcier said there is no evidence to suggest Maryk was involved in criminal activity, and he lost 50 pounds while in a Mexican jail cell.

Maryk was compelled to abduct his children because he was worried their mother was returning to a life of prostitution and drug use, Bourcier said. There is no chance Maryk would attempt such an abduction again, he said.

"Mr. Maryk had genuine concern his children were not being properly cared for," he said. "It was his view this was not a good place for his children."

Bourcier said Maryk chose not to appeal the court's decision to award custody to Cablek, but decided to take matters into his own hands.

"It was misguided and it was certainly criminal," he said. "His motivation was to try and take care of his kids."

The children were not exposed to criminal activity while with their dad, Bourcier argued.

"These kids were not prisoners in the home ... Mr. Maryk was doing his best in a difficult situation," he said. "He's not the monster the Crown is making him out to be. He's a father who made a bad mistake."