Police Scotland Chief Constable Phil Gormley has not been interviewed about misconduct claims seven months after the allegations were first made, his wife has said.
Claire Gormley, herself a former police officer, spoke out in defence of her husband, who is currently on special leave.
It comes as the independent Police Investigations and Review Commissioner (Pirc) is considering allegations of gross misconduct made against the force's most senior officer.
Writing in the Scottish Daily Mail, Mrs Gormley described herself as being an "experienced investigator" who had conducted a number of probes "including inquiries into allegations of bullying against senior officers".
She stated: "No one disputes the seriousness of bullying, but to ensure fairness to both the accused and the accuser, I interviewed key witnesses as soon as possible, obtaining untainted and relevant evidence."
In such cases she said she had "searched for the truth" but added: "I have seen little evidence of this concerning my husband, who seven months after the first allegation was made, has still not been interviewed.
"The Police Investigations and Review Commissioner's office says it is overwhelmed with work and has expressed concern that one aspect of the delay has been a degree of tardiness by some in the force to give evidence."
Mr Gormley, who denies the allegations against him, was placed on special leave in September and has not been back to work since - with the Justice Secretary Michael Matheson having hit back at claims he illegally blocked the Chief Constable's return.
Scottish Conservative leader Ruth Davidson said: "Seven months after the first allegation against her husband, Mrs Gormley says the chief constable has not yet been interviewed by the body conducting the investigation.
"She also claims that others in the force have not yet come forward to provide any evidence to the authorities.
"If this is all true, we have to ask what is going on? Why has the Scotland's police force been left without its chief for months and months, without basic enquiries having been made?"
Meanwhile Labour justice spokesman Daniel Johnson branded the situation a "farce".
He said: "When Matheson intervened, in what should have been an independent employment decision, he fuelled speculation and added to the controversy.
"This is now being played out on the front pages of the newspapers with an ever more diverse cast of characters, making a mockery of what is an incredibly important issue."
The Labour MSP added this was "precisely why" police watchdogs at the Scottish Police Authority (SPA) "should be independent of government, putting them beyond this kind of damaging slanging match".
A spokeswoman for the Pirc said it "continues to carry out thorough and independent investigations into the various allegations about the Chief Constable and recognises their significance".
She added: "In each case, the Pirc has progressed these enquiries timeously and is conscious of the needs of both the complainers and the Chief Constable, all of whom seek a speedy outcome to these investigations.
"Pirc investigators have interviewed a substantial number of witnesses as part of the evidence gathering process to ascertain the full nature of the allegations which have been made. It is right and proper that these interviews took place before interviewing the Chief Constable.
"In response to a request by the Pirc, the Chief Constable has now provided a list of dates on which he is available for interview and the Pirc investigators are working to facilitate the necessary interviews."