A couple, four actually in this omnibus edition from Dan Kavanagh aka Julian Barnes.
From Fantastic Fiction.....
Dan Kavanagh was born in County Sligo in 1946. Having devoted his adolescence to truancy, venery and petty theft, he left home at seventeen and signed on as a deckhand on a Liberian tanker. After jumping ship at Montevideo, he roamed across the Americas taking a variety of jobs: he was a steer-wrestler, a waiter-on-roller-skates at a drive-in eatery in Tucson, and a bouncer in a gay bar in San Francisco. He is currently working in London at jobs he declines to specify, and lives in North Islington.
Barnes is quite well known for his literary fiction. One of which I've even read - Flaubert's Parrot.
Early 80s he turned his hand to crime fiction with this series of four books featuring a bi-sexual PI.
I can't remember how many years I've had this one the TBR pile, ten at least. Another year or two won't make much of a difference, though I do hope to read them one day.
Things aren't going so well for Brian McKechnie. His wife was attacked in their home, his cat was brutally killed and now a man with a suspiciously erratic accent is blackmailing him. When the police fail spectacularly at finding out who's after him, McKechnie engages the services of London's most unusual private eye.
Duffy is a detective like no other. A bisexual ex-policeman with a phobia of ticking watches and a penchant for Tupperware. But what he lacks in orthodoxy he makes up for in street-smart savvy and no-nonsense dealings. Intrigued by McKechnie's dilemma and the apparent incompetency of his ex-colleagues, Duffy heads to his old patch, the seedy underbelly of Soho, to begin inquiries of his own.
Helped by some shady characters from his past, Duffy discover that while things have changed in the years since he was working the area, the streets are still mean and the crooks walk arm in arm with the blues. Full to bursting with sex, violence and dodgy dealings, Duffy is a gripping and entertaining crime novel with a distinctly different and entirely lovable anti-hero.
Fiddle City (1981)
There's suspicion, smuggling and shady goings-on galore in the second novel in Dan Kavanagh's darkly humorous series, featuring bisexual private detective Duffy.
Everyone knows a bit of petty theft goes on in the freight business at Heathrow - it is fiddle city, after all. But things have gone beyond a joke for Roy Hendrick and he suspects someone who works for him is helping themselves to more than they should. That's when he sets Duffy on the case.
A bisexual ex-policeman, Duffy runs a struggling security firm, has an obsessive attitude to cleanliness and can often be found propping up the bar at the Alligator. Duffy agrees to work for Hendrick and goes undercover to try and root out the culprit.
But things aren't all they're cracked up to be. What's the story behind the imperious HR manager Mrs Boseley with her permanently frosty demeanour? And is Hendrick really as honest as he claims to be? Duffy's up to his neck in it.