Am posting this with friend's permission. Her 8 month old son's father is from a European (non-EU) country and while he lives there, he has been back and forth to see baby a few times since birth. During visits he has stayed at a relatives house in our town. Baby has a passport though that was nothing to do with his father, friend went on holiday with her mum in August and that's why he has one. The baby's father has recently got quite forceful about contact and soon expects to be able to take the baby to see his family in his country for a period of time. Friend doesn't want that yet as baby is still very young and breastfeeding, and more importantly she does not trust him to bring him back.
Friend has recently found out he is coming over with his parents and older child in a few weeks to see the baby. Friend has faced online harassment from his mother (who speaks very little English, this is relevant because friend cannot communicate or reason with her) who keeps taking photos of the baby from her Facebook and posting them on her own account with captions that imply she is looking after the baby (or at least that's how Google translate reads it). Friend is terrified they are going to do a runner with her baby and take him abroad, she has someone else minding the passport so there is absolutely no chance they can get hold of it. The thing is he hasn't actually done anything wrong yet or made threats so she doesn't have much of a basis to go to authorities, though she is looking into speaking to someone.
The father also wants to get the baby official citizenship in his country (this is legally allowed, baby is considered a citizen as he has one parent who is a citizen).
Friend is worried about what to do when they all come over, he is on the birth certificate, pays child support and there aren't actually any safeguarding issues (friend is confident baby is not in any danger of abuse or neglect when with the father) so there is also no basis to not let them see the baby, but she is very uneasy about them taking him. Also if the father wishes can he seek legal grounds to take the baby out of the country for a certain amount of time? Friend has been doing lots of reading up and I've been trying to help but it's all very very confusing and seems to be situation dependant, and it's made more complicated by the fact there are 2 nationalities involved and citizenship etc.