Justice Secretary Humza Yousaf said language used in an internal police email on the deployment of female firearm officers is “utterly intolerable”.
An email seen by BBC Scotland asks that two female officers not be deployed together when a man is available, citing physical capacity and “a balance of testosterone”.
Police Scotland said the officer who sent the message earlier this year, then a temporary inspector, has apologised for the “unacceptable” wording.
The email reportedly read: “Im (sic) going to plunge in with both feet and open myself up to being accused of being sexist!
“For operational reasons I don’t want to see 2 x female officers deployed together when there are sufficient male staff on duty.
“This is based on my experience in the firearms and routine policing environment, other than the obvious differences (sic) in physical capacity, it makes more sense from a search, balance of testosterone perspective.”
“If you want to discuss my door is open.”
It concludes: “Ladies, For the purpose of transparency I have included you in this email.
“Likewise if you want to discuss my door is always open.”
Mr Yousaf told BBC Scotland: “That language is utterly intolerable.
“That is not the kind of language I would expect any police officer, junior or senior, to be using but it will be for the chief constable, undoubtedly, to investigate and we will leave that in his hands.”
Police Scotland has 572 Authorised Firearms Officers - 539 male and 33 female.
Two former female firearms officers are taking legal action against the chief constable on the grounds of discrimination.
Chief Superintendent Matt Richards, divisional commander for specialist services, said: “The email was dealt with immediately and the matter was investigated fully.
“The officer fully accepts the wording was unacceptable and does not meet our values of fairness, integrity and respect.
“He was spoken to by senior management and issued with corrective advice. The officer has apologised and the matter was dealt with internally.”