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 a period of special leave.
It comes as the independent Police Investigations and Review Commissioner (Pirc) considers allegations of gross misconduct made against the service’s most senior officer.
The Pirc is currently investigating three allegations, and is examining another complaint to see if it should be investigated.
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.”
She added if the “simple investigation had been properly conducted, this could have been dealt with in a few weeks”.
Mr Gormley, who denies the allegations against him, was placed on special leave in September and has not been back to work since.
His lawyer David Morgan has already raised concerns the investigations have suffered from “significant delays”.
The Pirc has been contacted for comment.