The Northern Ireland Secretary has joined those questioning the actions of the Deputy First Minister in attending an IRA veteran’s funeral that saw hundreds of people line the streets.

Michelle O’Neill has faced calls to resign following Bobby Storey’s funeral in west Belfast on Tuesday.

Police are investigating potential breaches of coronavirus lockdown rules that restrict outdoor public gatherings to 30 people.

A picture posted on social media by a Sinn Fein branch in the Irish Republic showed Ms O’Neill posing for a selfie close to two men, one of whom had his arm on her shoulder. The picture was subsequently deleted.

On Wednesday, the Deputy First Minister defended the event, saying the cortege only had 30 people in it and social distancing inside the church was “exemplary”.

Secretary of State Brandon Lewis questioned the attendance of Ms O’Neill and other Sinn Fein executive ministers.

Mr Lewis said he understood that some people were “frustrated and angry” at what happened.

“I was a bit surprised… when you are saying to people you’ve got to follow those guidelines,” he said.

“People have given so many sacrifices over the last couple of months, particularly in Northern Ireland where we have seen people really strongly following the guidelines, we’ve seen lower levels of things because people are following those guidelines so well.

“I am surprised we would have someone from the executive of any description being in a position where it would be perceived to be that they are not doing that.”

Her told BBC Radio Ulster: “I can understand people’s frustrations. It’s not something I would have done.”

Ms O’Neill insisted everything was done “in accordance with the guidelines”.

“Regrettably a considerable number of family members were unable to take part in the cortege as a result of the current restrictions, like many other families who have been unable to properly grieve or mourn the loss of a loved one in a traditional way as a result of the Covid crisis,” she told the Irish News.

“These restrictions have been very difficult for families who have lost a loved one and particularly those who lost a loved one during the period when society was in lockdown.”

On Tuesday, Stormont health minister Robin Swann said the funeral must not become Northern Ireland’s “Dominic Cummings moment”.

Mr Swann said the scenes in Andersonstown, where roadsides were packed with people as the cortege carrying Mr Storey passed by, was a clear breach of Stormont restrictions.

Sinn Fein president Mary Lou McDonald and former leader Gerry Adams were among other high-profile party members at the service and a later commemoration event at Milltown cemetery.

Ms O’Neill in particular has faced strong criticism from political rivals in Northern Ireland, given her role as the joint head of a Stormont Executive that has been instructing people to limit the size of funerals during the lockdown.

Mr Swann’s weekly Covid-19 media conference was dominated by the issue on Tuesday as he was challenged on whether the executive’s credibility had been undermined.

He was asked if the incident could lead the public to question the point of abiding by the rules – the way some people did after the Prime Minister’s top adviser Mr Cummings was accused of breaching regulations during a trip to the North East of England during lockdown.

“I sincerely hope that this isn’t the Dominic Cummings effect in Northern Ireland because in our health service we can’t afford it to be,” he said.