WASHINGTON (AFP) - Hit US TV series CSI: Crime Scene Investigation is ending in September, after a 15-year run and more than 300 episodes of high tech whodunits, CBS television has announced.

The network promised an "epic" two-hour CSI season finale on Sept 27 featuring its original stars, William Petersen and Marg Helgenberger alongside current star Ted Danson.

"We actually got a little misty-eyed about this one," said Nina Tassler, who heads CBS Entertainment.

The series, the longest running scripted primetime production, already has had three spin-offs, including CSI: Miami, CSI: NY, and CSI: Cyber, the latest.

Danson and his character, D.B. Russell, will move to Cyber, teaming up with Patricia Arquette as Dr Avery Ryan, PhD, CBS said.

The series, which drew 25 to 30 million viewers at its peak in 2007, revolves around a team of crime scene investigators working for the Las Vegas Police Department who use physical evidence to solve crimes.