Hagan Homes, one of Northern Ireland's biggest property developers, said its houses "fit for part-time royalty' ads were meant to be "light-hearted".

It did not have the couple's permission and has been told to remove the ads.

The firm said it had not intended to cause any offence and it has offered to make a £10,000 donation to charity.

On Friday, the Belfast Telegraph reported that representatives of the duke and duchess were to take "action" over the advertising campaign.

The adverts, which appeared on Belfast billboards and on social media, featured photos of the Duke and Duchess of Sussex with worried expressions.

"Buying a new home can be rather stressful," one of the adverts stated.

It followed an announcement from the couple earlier in January in which they said they intended to "step back" from royal duties and become "financially independent".

It was also confirmed that they wish to repay the £2.4m of public funds spent on the refurbishment of their UK home, Frogmore Cottage.

'Role models'

In a statement on Saturday the founder and chairman of Hagan Homes, James Hagan, said the firm was in the process of removing all the adverts.

"We have been in contact with representatives for the Duke and Duchess of Sussex and taken action to remove the social media posts and billboard advertising," Mr Hagan said.

"The 'Hagan Homes Fit For Part-time Royalty' campaign was intended to reflect Northern Ireland's typically light-hearted approach to a challenging situation.

"Many young people struggle with the complexities of buying a new home and we were keen to emphasise that support is available in such circumstances."

He added: "It was not our intention to cause any offence and we sincerely apologise if any has been taken.

"We believe Harry and Meghan are strong role models for all young people who are trying to find their own path in life and in recognition of this Hagan Homes is keen to make a donation of £10,000 to a charity of Harry and Meghan's choice."

Advertising rules

A spokeswoman for Hagan Homes confirmed to BBC News NI that the firm received an email from the couple's representatives, requesting the adverts be taken down.

She said the email referred to rules from the Committees of Advertising Practice (CAP).

The rules makes specific mention of the Royal Family, saying its members "should not normally be shown or mentioned in a marketing communication without their prior permission".

Hagan Homes, based in Ballyclare, County Antrim, has already deleted its social media adverts and said its billboard adverts will be be "taken down by close of play" on Monday 27 January 2020.