Scottish First Minister Humza Yousaf said she was not misled by Michael Matheson in the revelations about the iPad data roaming bill, but the health secretary “should have handled the situation better”.
The First Minister has defended Mr Matheson as “a man of integrity” as a possible motion of no confidence in him looms at Holyrood.
The Scottish Government's health secretary admitted on Thursday that his teenage sons used data from his Holyrood-issued iPad to watch football matches while on holiday in Morocco, running up a roaming bill of almost £11,000.
Despite initially insisting the device was used for parliamentary work during the family trip in December and early January, he revealed he had recently discovered his family's involvement but initially withheld the information to “protect” the children of.
In his personal statement to the Scottish Parliament he said he informed the Prime Minister of the truth on Tuesday.
The next day, Mr Yousaf told the PA news agency that the matter was “now closed” despite the new information.
On Sunday, Mr Yousaf appeared on BBC Radio 4's Broadcasting House show, where he was asked whether Mr Matheson had misled him.
The Prime Minister said Mr Matheson had only used the iPad for parliamentary purposes and only discovered his sons' use of the data at the end of last week.
Mr Yousaf said: “There is a reasonable question that people have asked, and Michael answered last week, about whether at that point he should have spoken upfront publicly about the fact that this was the reason he chose to pay off the bill in full.
“He was trying to protect his children.”
He continued: “To me, Michael – whom I have known for 15 years – is a man of integrity, honesty.
“He should have handled the situation better, Michael knows that and he apologized for it.”
He added: “No, I don't believe Michael did (mislead me).”
Scottish Conservative leader Douglas Ross said Matheson was “hiding” from scrutiny.
The Moray MP said only his party could move a motion of no confidence in the Health Secretary.
Appearing on BBC Scotland's Sunday programme, he commented that neither Mr Yousaf, Mr Matheson nor the deputy first minister had agreed to appear on the programme.
Mr Ross said: “This affects all levels of government in Scotland because none of them are willing to talk about the really important issues.
“Because they cannot and will not defend this Minister of Health, who should have resigned by now and Humza Yousaf should have fired him.”
Scottish Labor leader Anas Sarwar also appeared on the Sunday Show, reiterating his call for the health secretary to resign.
Mr Sarwar said: “I don't think the Prime Minister or Parliament should have any confidence in Michael Matheson, he should resign.
“He says he discovered the truth on Thursday, but continued to tell the public untruths for days afterward.
“He says he told the Prime Minister on Tuesday, the Prime Minister also said inaccuracies the next day. This is not acceptable in public life.”