Currently watching the film now, interesting cast, "interesting group", From Columbo there is the man himself,
Bert Freed
&
Suzanne Pleshette
Janet Margolin
Martin Landau
Val Avery

Always fun to see movies with a host of Columbo actors/actresses in.

I wonder what movie contained the most Columbo stars?

Even though they aren't the only place to look, TV movies (especially ones that coincided with Columbo as far as the years, or came close) are a good place to look.

One I can name is THE BROTHERHOOD OF THE BELL from 1970.
Rosemary Forsythe
Dean Jagger
Maurice Evans
Will Geer
Dabney Coleman
James McEachin

Suzanne Pleshette and Val Avery were both in an episode of The Invaders, called 'The Mutation'.

I haven't seen it in some time, but ESCAPE FROM THE PLANET OF THE APES has Roddy McDowall, Kim Hunter, Bradford Dillman, Sal Mineo, William Windom and Ricardo Montalban.