The First Minister told MSPs today that Mr Matheson acted "entirely appropriately" when he intervened to question a Scottish Police Authority's plan which would have seen sidelined Chief Constable Phil Gormley return to duty .
But the Conservatives are now demanding a change in the law to make scrutiny of the national force more transparent.
Mr Matheson has been criticised for demanding to know whether due process had been followed - which resulted in the Mr Gormley's return being blocked. He is currently on special leave while investigations are carried out into allegations of gross misconduct.
Ms Sturgeon told MSPs at First Minister Questions: "The Justice Secretary has acted entirely appropriately."
The SNP leader insisted that opposition parties, like the Tories, would have been quick to criticise Mr Matheson if he had failed to check that procedures had been followed.
"The hypocrisy of the Tories on this is quite breathtaking," Ms Sturgeon added.
"The Justice Secretary did his job and he did his job properly on behalf of the people of this country."
Mr Gormley's lawyers have threatened to sue the Scottish Government over the intervention by Mr Matheson, claiming it was unlawful. The Justice Secretary also faced awkward question when it emerged that no minutes had been taken of the meeting with the SPA.
Davidson said: "We have promises to be transparent while meetings are taking place without any record of what is going on.
"It's the SNP's `Secret Scotland' and it stinks."
She called for a chnage in the law ensure MSPs at Holyrood have "more power" in scrutiny of the national force, instead of the Scottish Government.