The Health and Safety Executive has sought social distancing details from three airports in Northern Ireland.
Pictures shared of Aer Lingus' George Best Belfast City Airport to London Heathrow flight on Monday morning showed row after row filled with passengers.
Stormont's health minister Robin Swann criticised the airline amid evidence of an almost full cabin with no apparent social distancing.
The Health and Safety Executive for Northern Ireland's (HSENI) chief executive Robert Kidd said: "We have been in touch with all three airports asking them to confirm what social distancing measures are in place."
The HSENI is responsible for enforcing and informing workplace safety.
That includes at Belfast City, Belfast International and City of Derry airports but does not extend to on board the aircraft themselves.
Mr Kidd said the City Airport was the only one in Northern Ireland carrying passengers during the pandemic.
Today he told Stormont economy committee members: "I am assured that they have improved social distancing measures and additional staff to help remind passengers as they travel through the airport.
"One of the challenges around an aircraft is the very small and confined space and it will add to the timing of loading passengers on to adhere to social distancing.
"That is one of the real challenges going forward."
The Civil Aviation Authority is responsible for matters involving aircraft.
Mr Kidd said Aer Lingus had taken action.
He added: "My understanding is that Aer Lingus have now recognised that and took a decision to run two flights rather than one busier flight."
The airline on Tuesday evening announced it was adding an extra flight to the route and making changes to boarding procedures.
It advised all customers to give themselves additional time to check in, as changes to the boarding procedure will be introduced and more luggage will be checked into the hold.
The chief executive of Belfast City Airport, Brian Ambrose, said it was working "around the clock" to make it as safe as possible for travellers.
Mr Ambrose said Monday saw the first big influx of passengers since the virus outbreak, with 154 on the flight.
Until Monday only 30 or 40 passengers had been using the Heathrow flight and were mainly medical workers.
It is expected to be late summer before the airport begins opening some of its cafes or restaurants and stemming its significant losses.
