Stormont’s First Minister has called on the Deputy First Minister to apologise over an IRA veteran’s funeral that saw hundreds of people line the streets.

Arlene Foster’s comments come as Michelle O’Neill faces calls to resign after she and party colleagues attended 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.

Mrs Foster said the scenes at the funeral and apparent lack of social distancing had “undermined the credibility” of Stormont’s Covid-19 guidance.

The DUP leader said it sent out a message of “do as I say and not as I do”.

“She needs to apologise and recognise the wrong that has been done and she absolutely needs to make amends for what happened yesterday and take steps to try and build up that credibility again,” said Mrs Foster.

“It is really regretful that we are talking about this today.

“Many people have had to go to through mourning and grief during this time and haven’t had the comfort of people coming to their homes, they haven’t had the comfort of a full service, yesterday they asked ‘well why was that the case?’.”

Ms O’Neill said the funeral had taken place “in accordance” with coronavirus guidelines.

She has defended the event, saying the cortege only had 30 people in it and social distancing inside the church was “exemplary”.

Earlier, 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.”

He 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.