Police say no prosecution will take place into the death of Joshua Titcombe or any other babies at the maternity unit at the Furness General.
The baby, from Dalton-in-Furness, Cumbria, died nine days after he was born at the hospital 2008.
His father, James, refused to accept the explanations he was given for his son's death and successfully argued for an inquest which, in 2011, heard that midwives repeatedly missed chances to spot and treat a serious infection.
Joshua's observation chart went missing and has never been found, while a coroner accused midwives of "colluding" over mistakes made.
Police began an investigation into Joshua's death before the inquest and later widened their probe to look at the deaths of 18 other babies and two mothers at Furness General.
In 2012, detectives said no action would be taken in relation to the deaths except the case of Joshua Titcombe, which had been passed to the Health and Safety Executive (HSE) for its consideration
Detectives also investigated 14 births which involved complications, but also recommended that no action be taken in relation to them.
Today, Cumbria Constabulary announced the HSE had notified them that it would not be carrying out any further investigations.
Last month, an independent report - chaired by Dr Bill Kirkup - uncovered a "lethal mix" of problems at the "seriously dysfunctional" maternity unit, which led to the Health Secretary describing the unnecessary deaths of 11 babies and one mother as a "second Mid Staffs".
Police said today that the Morecambe Bay Investigation, which was separate from the criminal probe, did not raise "any further issues of significance that were not already known to the investigation team".
Senior investigating officer Detective Inspector Doug Marshall said: "Although we have not been able to progress to a criminal prosecution, I am confident that it was right for us to undertake a police investigation.
"Our investigation meant that other agencies also began looking at what was happening at Furness General Hospital, and it assisted families in getting the independent investigation that they deserved.
"As the Report of the Morecambe Bay Investigation stated, it was always going to be difficult for the police to reach the bar for prosecution, however it was in the public interest for us to investigate these serious complaints as thoroughly as possible.
"I would like to take the opportunity to thank the families involved for their support and patience during a lengthy and complex investigation.
"I hope that our investigation and the Report of the Morecambe Bay Investigation have, in some way, addressed their concerns and brought them out into the open.
"However nothing can ever bring back those that they have tragically lost, and our thoughts remain with them. I share the hope that lessons have been learned and the necessary improvements made."
Speaking at last month's unveiling of the independent report, Mr Titcombe said the police investigation into his son's death was not an "important issue" for him.
He said: "If I am honest with you, I think this (Morecambe Bay) investigation gets to the truth. What good would the HSE prosecution do in fining a trust that is already struggling for money?
"So it's not an important issue for me. What's important is the recommendations of this report are implemented. There has been progress in patient safety, let's carry on that now, let's commit to 10 years of driving to change the culture."