Derry Girls star Nicola Coughlan has called out a theatre critic for commenting on her weight in two separate reviews.

The Galway-born actress, who plays Clare in the hit Channel 4 comedy series, is currently starring in the play The Prime of Miss Jean Brodie at Donmar Warehouse in London and it's garnering positive reviews.

On Thursday, the 31-year-old star of the screen and stage took to Twitter to draw attention to a review of the play by Philip Fisher for the British Theatre Guide, an independent website featuring reviews, news and podcasts.

She posted a screengrab of a portion of his review which referred to her character as a "kind of overweight little girl" and wrote: "Hi @BritTheatreGuid, for the second time your reviewer Philip Fisher has come to see a show I’m in, and as part of reviewing the show he has also reviewed my body. 

"How can you continue to support this?"

Coughlan went on to explain that Fisher also commented on her weight when he reviewed her play Jess and Joe Forever last year, saying he opened the review with the sentence "Jess is a fat girl".

"My weight has no relevance to either the performance I gave in that or in The Prime of Miss Jean Brodie", she wrote.

The actress also drew attention to the critic's description of a rape scene from another play, before adding: "Philip Fisher, I know you are a theatre reviewer and your body had no relevance to your job but maybe you'd like me to cruelly review it for you and post it online?"

She tweeted to the British Theatre Guide that she is "so disappointed you let a man like this review for you."

"Let me state this clearly, he is not welcome to review any show I am in from now till forever. And I plan to be in a lot of damn shows", she concluded.

Derry Girls creator and writer Lisa McGee retweeted Nicola's first tweet, with the caption, "This is unacceptable".

The British Theatre Guide responded to Coughlan by saying they "apologise unreservedly for the offence caused by the wording of this review."

They tweeted: "The offending words have been removed. While the reviewer may not have intended to offend, he accepts that it is not acceptable to use such descriptions in a review and not BGT policy."