The Doobie Brothers have slammed Bill Murray in a hilarious legal letter.

The veteran rockers have threatened to take action against the 'Groundhog Day' star for allegedly using their music without permission in adverts for his golf apparel line, William Murray, and took a swipe at the 70-year-old actor's career in a warning message from their attorney, Peter Paterno.

Accusing the company of using their song 'Listen to the Music' without paying for the privilege, the letter read: ''It's a fine song. I know you agree because you keep using it in ads for your Zero Hucks Given golf shirts.

''However, given that you haven't paid to use it, maybe you should change the company name to 'Zero Bucks Given.' ''

And the lawyer alleged the Doobie Brothers weren't the only artists not being paid for the use of their music in the company's commercials.

It continued: ''We understand that you're running other ads using music from other of our clients. It seems like the only person who uses our clients' music without permission more than you do is Donald Trump.''

And the lawyer - who also represents Metallica and Dr. Dre - even suggested Bill faces ''eternal damnation'' for his 'Garfield' movies and branded his golfwear ''so damn ugly''.

The letter continued: ''This is the part where I'm supposed to cite the United States Copyright Act, excoriate you for not complying with some subparagraph that I'm too lazy to look up and threaten you with eternal damnation for doing so.

''But you already earned that with those 'Garfield' movies. And you already know you can't use music in ads without paying for it. We'd almost be OK with it if the shirts weren't so damn ugly. But it is what it is.

''So in the immortal words of Jean Paul Sartre, 'Au revoir Golfer. Et payez!'''