The DUP MLA Alex Easton has apologised after he was caught on camera shopping for shoes during Thursday's health committee.
He explained his shoes had been worn through and no shops were open.
"But that is not an excuse," he said.
First Minister Arlene Foster said at a Stormont press briefing on Thursday that Mr Easton was wrong to be shopping online during the committee.
"Alex has acknowledged he should not have been doing that," she said.
"I think what we all need to do is ensure we work very hard to deal with all the issues in front of us."
Cameras in the senate chamber caught the North Down MLA on his laptop looking at a pair of shoes. Footage was broadcast on the Assembly's coverage of the committee.
It had been discussing the Public Health Agency's response to the coronavirus pandemic.
Mr Easton, who sits on the health committee, took part in the hearing. He had asked officials about the number of outbreaks of the virus had been found in care homes.
In a statement to the Belfast Telegraph Mr Easton apologised, saying it would never happen again.
“I apologise unreservedly for disrespecting the Committee," he said.
"My shoes were worn through. The shops are closed. But that is not an excuse, I should have found time outside of the committee to resolve the matter.
"It will not happen again. I have written to the Assembly Speaker and the Committee Chair to apologise.”