Six men who were arrested in connection with an alleged serious assault in Sunderland have been released with no further action.
Police received a report that a 26-year-old woman had been attacked in a house in Peel Street overnight between Saturday, September 3 and Sunday, September 4.
A spokesman for Northumbria Police said: "At the time six men were arrested and since the incident detectives carried out extensive enquiries in to the assault.
"Earlier this year, the case was submitted to the Crown Prosecution Service for a decision, it was found the case of five men did not meet the threshold for a charging decision from the CPS. The file against one man was reviewed for a decision by prosecutors on whether or not the man would be charged.
"The CPS have reviewed the case and have informed police the man will not face any charges. All of the six men arrested have now been released with no further action."
Superintendent Paul Milner said: "Our utmost priority is the victim and making sure she has the full support she needs.
"We know it takes great courage to come forward and report incidents like this to police and would like to offer our reassurance we have officers who are specially trained to deal with the sensitivities of incidents of this nature.
"A full and thorough investigation has been carried out by specially trained, dedicated and experienced detectives who have spent considerable time pulling together the facts to submit to the crown prosecution service.
"Our investigation remains open and if any further information does come to light this will be fully investigated."
A CPS Spokesperson said: "On 24 March, the CPS received a file of evidence in relation to an attack alleged to have taken place at an address in Peel Street, Sunderland on Sunday 4 September last year.
"After careful consideration we have decided that no further action should be taken against the individual suspect for whom we were asked to make a charging decision by police.
"In this case, there was insufficient evidence to provide a realistic prospect of conviction, in accordance with the evidential test set out in the Code for Crown Prosecutors."