Concerns were raised after a police officer spoke with the mum and boy after meeting them at the nature reserve in Whittlesey.
A spokesperson for Cambridgeshire police said: “As police officers, we come across a whole range of different things each and every day we come into work.
“Yes, we lock up criminals, but in everything we do our aim is to keep the people of Cambridgeshire safe.
“Last week one of our neighbourhood policing officers was on patrol at the nature reserve in Whittlesey when he came across a woman and child who he spoke with.
“Something didn’t sit right with him, so he arranged to visit them at their home at the weekend to check in on them and have another chat.
“Sadly, what the officer was met with at the home was of concern – the living conditions and condition of the child were not suitable for the young boy.
“A police protection order (PPO) was put in place meaning the child has been removed from the home and put in the care of other family members, with the aim of reuniting them once his mother has the help she needs.
“Substantial safeguarding referrals have been submitted, with plans in place to continue welfare visits over the coming weeks.
“A lot of this area of work we do often goes unseen, but please be assured we will act on information we receive where someone has concern for a child.
“You can find out more about what to look out for and how to report concerns on our website here https://bit.ly/3fBytlG.”