A police watchdog has called for greater clarity on how forces work together - after a man strangled a woman with her hair straighteners while on bail for two rapes.

Significant failings were highlighted by the Independent Police Complaints Commission (IPCC) in how Kent and Greater Manchester Police dealt with allegations against Lee Nolan.

Nolan, 48 and from Heywood, Manchester, was convicted of murder in February this year at Manchester Crown Court.

The IPCC examined how Kent and GMP investigated two alleged rapes and an alleged threat to life by Nolan, which were unrelated to his later conviction.

The IPCC looked at whether GMP and Kent investigations had been full and thorough in the two separate incidents that were reported to them in July 2014.

It was found that the first report of threats to kill by Nolan was never progressed by either Kent Police or GMP.

There was confusion over which force would investigate the threat to kill as Kent thought Nolan had been in Manchester at the time the offence was alleged but GMP were unaware of this.

IPCC Deputy Chair Rachel Cerfontyne said: "No force took responsibility for investigating this threat to kill.

"The lack of organisation and inadequate communication meant that grave offences were not investigated.

"Whilst it is impossible to know the full consequences of this failure, we do know that Mr Nolan remained at liberty and went on to commit murder, albeit unrelated.

"It is essential that forces have protocols in place which ensure effective policing nationwide.

"I strongly recommend an urgent review of current policies and practices and will be taking this forward with relevant policing bodies.

"In this case, the failure of either force to assume primacy, resulted in a serious offender being left at large and the public not protected from him."

A further allegation of rape also suffered from severe delays and poor communication with the victim.

Two Detective Constables, one from Kent Police and one from GMP, were found to have cases to answer for misconduct in failures to progress investigations and failing to obtain evidence requested by the Crown Prosecution Service in an appropriate time frame.

They were subject to management action.

Kent Assistant Chief Constable Jo Shiner said: "The Independent Police Complaints Commission’s report into the handling of this incident makes for disappointing reading.

"Kent Police places a clear expectation on all its officers and staff that victims must be put at the heart of everything we do, but it is clear that there was an unacceptable level of confusion and lack of communication between police forces in this investigation which took place in 2014.

"Following the IPCC’s investigation one officer, a detective constable, received management action having not progressed certain enquiries that were expected of her during the crime investigation, and for failing to provide an appropriate handover before a period of leave.

"In its report, the IPCC agreed this was the most appropriate discipline outcome.

"Kent Police has since evolved to include enhanced dedicated teams of specialist rape and serious sexual offence investigators.

"This has continued to raise the level of investigative standards and support to victims through closer supervision.

"Kent Police continue to strive to deliver the very best quality of service to victims and witnesses, particularly those who are most vulnerable.’