Two more people have been arrested following a "vicious attack" on an elderly couple during a break-in.
A 90-year-old man suffered throat injuries while his wife, in her 80s, sustained head injuries when they were assaulted in their home in Elm Grove, Scunthorpe, on Tuesday evening.
A 22-year-old man has been arrested on suspicion of aggravated burglary, while a 27-year-old woman was held on suspicion of assisting an offender.
The elderly couple remain in hospital in a stable condition, Humberside Police said.
A 36-year-old man arrested on Christmas Eve has been released on police bail pending further inquiries.
Scunthorpe manager Alan Knill has said his club's poor start to the season has been put into perspective after a near-calamitous accident with a squirrel.
He told BBC Radio Humberside he almost suffered a serious injury when his bicycle hit the animal.
"I went over the top of my bike and landed on my head, shoulder and neck.
"I saw it run into the road but couldn't do anything about it and it just hit my wheel and stuck in my wheel and hit my brakes.
"For a minute, I thought I might have been in trouble because I landed on my head. Then, all of a sudden, I thought: 'I'm not, I'm alive!'"
Scunthorpe are bottom of League One after losing their last six matches.
A post mortem examination of the baby found at Bell Waste Control in Scunthorpe has confirmed that it was a newborn baby boy.
The cause of death is yet to be established as the results came back inconclusive and further tests will now be carried out.
The teenage mother remains in hospital receiving medical care and police inquiries into the circumstances of what happened are continuing.
A teenager has contacted police to say she is the mother of a baby boy found dead in waste being sorted at a recycling plant.
Officers received a telephone call yesterday from a girl who was in a distressed state, reporting that she was the mother of the baby found at Bell Waste Control in Scunthorpe.
The teenager was taken to Scunthorpe General Hospital where she has been admitted for post-natal care, a spokeswoman for Humberside Police said.
A local teenager has contacted Humberside Police to say she is the mother of a baby whose body was found amongst rubbish at a recycling plant in Scunthorpe, the force said.
The manager of the waste recycling plant in Scunthorpe where the body of a baby was found this morning says the body of the baby would have been in the rubbish for up to two days.
A worker found the corpse on a sorting conveyor belt in the Bell Waste Control processing plant. He initially thought it was a doll.
Police investigating the discovery of baby's body in Scunthorpe say they are concerned about the health of the baby's parents.
Staff at the Bell Waste Control discovered what is believed to be the body of a six-month old baby boy this morning. A spokesman for Humberside Police said: