A New York Fire Department captain has been exposed as living a 'double life' as a rapper who sings lyrics about violence and projects an 'anti-cop image'.

FDNY Captain Kaseem Ryan, 44, who is assigned to Engine 235 in the Brooklyn neighborhood Bedford Stuyvesant.

However Ryan also goes by the name Ka, who sang in a 2013 song: 'F- -k them cops and swats with night vision. I see your traps and your plots to dead us, y'all rolling with Kojaks, n- - -a, I got Berettas.'

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Double life: FDNY Captain Kaseem Ryan is assigned to Engine 235 in Bedford Stuyvesant, but he is also Ka, a rapper who sings about the 'ghetto life'

Ryan (right) is a veteran of the FDNY. He is seen here with some of his Engine 226 comrades

Ryan was outed as having the alter ego by The New York Post on Sunday.

He is a veteran firefighter who commands Engine Co. 235 and has performed with Wu Tang Clan's GZA.

Ryan addressed living a double life in a 2015 interview, however he did not reveal that he worked for the FDNY.

'I'm living two lives, man,' he said.

'I'm trying to be who I am in the day and then trying to feed my soul at night with being the artist that I want to be.'

Alter ego: Ryan has reportedly tried to keep his music career hidden at work

Ryan earned $148,558 as a fire captain last year.

According to Ed Mullins, president of the Sergeants Benevolent Association, Ryan's day job is completely at odds with his rapping persona.

'The biases he portrays through his music are indicative of what he believes or feels,' Mullins told The Post.

'As a New York City firefighter, he should be trying to bring people together rather than fracture relationships, especially in communities of color.'

Strong lyrics: Ryan's songs project an 'anti-cop image', even though he works for the fire department

On one of Ryan's songs, Mr. Officer, he speaks about police brutality against black youths.

'Why do you wanna see me in a coffin, sir?' he asks in the song.

Ryan would not comment on his rapping career when contacted.