The father's imprisonment has been difficult for the family, who have had to cope with a parent in the meantime.

- I was quite sad, because it is difficult to have only one mother at home, says Bob.

"Called every day"

Through the children's rights organization Bufff, which works to support children with parents deprived of their liberty, he got to know 9-year-old Julia who has similar experiences.

- Sometimes it can feel difficult.

But I got to talk to Dad, he called every day.

Bob and Julia are actually called something else.

Hear them tell more in the clip.