A FORMER doctor branded “northern birds” as “lazy, ugly w****** who smell of burgers” in an offensive song.

The medic turned writer, who worked on the script of hit TV show Mrs Brown’s Boys, also mocked infants with Down’s Syndrome in one of his tasteless tunes.

The words were written in a series of songs for his band.

The 39-year-old from Brighton drew plaudits for his memoir, This is Going to Hurt, an insight into his life as a junior doctor.

The book, released in September 2017, is described on his website as a “multi-award-winning, million-copy bestseller”.

But, in his time working in hospitals, he was also half of the musical parody band Amateur Transplants with former colleague Suman Biswas, who left the act in 2011.

They achieved moderate success in 2005 with the track London Underground, set to the tune of Going Underground by The Jam, which was widely circulated online.

The song slammed workers on the rail service as “lazy, f***ing useless c****” adding “they’re all greedy c****, I want to shoot them all with a rifle”.

It was at a similar time that the pair co-wrote the derogatory lyrics in a song called “Northern Birds”.

Many versions of the lyrics online have since been deleted.

Lyric site Genius.com, which previously had the words, now displays a page which says “oops, page not found, sorry, we didn’t mean for that to happen” when viewers attempt to access it.

The lyrics said: “You’re much better staying in the South. Northern birds are desperate ugly hippos.

“Dressed in burberry, with a peanut for a brain and an accent that makes you want to die.

“Now you’ve been warned, they’re all physically deformed. Northern birds are all obese and they’re riddled with disease.”

Amateur Transplants also wrote another song called Your Baby which asked mothers: “How do you feel about termination?”

It continues: “Your baby’s got a flattened nose, a widened gap between its toes.

“It’s smaller than it’s supposed to be. The scan shows your baby’s got an imperforate rectum.

“And there’s a big hole in his atrial septum. He’s got the signs of left heart failure.

“And quite abnormal genitalia.”

Mr Kay has since apologised “unreservedly” for the cruel words.

He said: “As a medical student more than 15 years ago, I was part of a group that recorded some songs for a ‘RAG week’ charity album, including a couple in terrible taste that crossed a line.

“I hugely regret my part in it and apologise unreservedly for the offence I have unthinkingly caused.”

Mr Kay left his career in medicine several years ago to become a full-time writer.

Last month he released another book, “Twas The Nightshift Before Christmas”, a series of tales of his time working for the NHS over Christmas. He also has a sold-out show at the Vaudeville Theatre in London later this month and is preparing for a tour early next year in which he will perform in venues across England.