In his report, Mr Pascoe said he had no doubt that the complainant had provided "compelling prima facie evidence of serious and unwelcome sexual behaviour" carried out towards her by Mr Hancock.
He described the woman as "a straightforward and vulnerable person, angry and hurt by what she said had happened to her".
He also acknowledged that Mr Hancock was not motivated "solely by sexual desire" and that he had sought to help her "wholly properly" as a local councillor.
"That said," he concluded, "I consider that the prima facie evidence of his unwelcome sexual approaches remains unquestionably a very serious matter in the light of the position which he holds and his knowledge from the beginning of the vulnerability of [the complainant].
"No one in public life should allow themselves to act in such an irresponsible and damaging way."
In a statement posted on the MP's website, a spokesman for Mr Hancock said that he had not yet given evidence to Mr Pascoe and that his report was therefore likely to be "one-sided".
"These matters have twice been looked at by the police, first in 2010, and in conjunction with the Crown Prosecution Service, they have found that there is no case for Mr Hancock to answer and have taken no further action," the spokesman said.
"Portsmouth standards sub-committee has yet to meet to hear evidence including from Mike Hancock as it decided to postpone that hearing until after the associated civil court case.
"Unfortunately due to the ongoing civil case, Mike received legal advice that he should not give evidence to the council's investigator. He looks forward to giving his evidence when the sub-committee meets after the conclusion of the civil case."
Mr Hancock has always denied the accusations and says that he will vigorously contest the civil case now being brought by the complainant.
The MP has been accused of making repeated physical sexual advances towards the woman, a young mother who had asked for help with noisy neighbours, despite being made aware she suffered a mental health disorder and had been sexually abused as a child.
After a previous investigation by Hampshire Police found there was no case to answer, Mr Pascoe was appointed by Portsmouth City council as an independent investigator to look into claims he had broken the council's code of conduct.
