The Garda Commissioner says the force will investigate how a member ended up participating in a photocall organised by a group calling for a Yes vote in the referendum on same-sex marriage.

Noirín O'Sullivan insists the force is apolitical and members should not be seen to take sides in the campaign.

Earlier An Garda Síochana said that their participation in an event in relation to the same-sex marriage referendum campaign was "not appropriate".

An event took place in Dublin yesterday, aimed at encouraging people to register to vote in the referendum.

The gathering saw uniformed members of An Garda Síochána, Former Supreme Court Justice Catherine McGuinness and representatives of a number of political parties.

A member of An Garda Síochana (left) with Justice Catherine McGuinness (right) at the event | Image: Richard Chambers

It was organised by the Yes Equality campaign.

But in a statement today, the gardaí say: "While the event was held in good faith to promote the fact that people can register at garda stations to vote in the upcoming referenda, it was not appropriate for this kind of photocall to take place given An Garda Siochana's status as an apolitical and impartial organisation."

The Transport Minister Paschal Donohue says it is 'essential' that the gardaí remain politically independent.

Originally posted at 13.40