The 48-year-old former Daily Mirror and News of the World editor was interviewed under caution at the end of 2013 by officers investigating claims of illegal voicemail interception by Mirror journalists.
In a statement Morgan said: “In early November I was asked to attend an interview by officers from Operation Weeting when I was next in the UK.
“This was further to a full witness statement I had already freely provided. I attended that interview as requested on 6 December 2013.”
The Mirror Group was brought into the phone-hacking investigation in March 2013 when Operation Weeting detectives arrested four journalists in dawn raids.
Arrested in the raids were Sunday People editor James Scott and deputy editor Nick Buckley, then heavily-pregnant former editor of the Sunday Mirror, Tina Weaver, and the former deputy editor Mark Thomas.
The allegations against them focus on activities at the Sunday Mirror around 2003 and 2004.
CNN has been aware of this interview since before it took place, and has no further comment CNN statement
The former Daily Mirror editor Richard Wallace has also been interviewed by police the day after his four colleagues were questioned.
While Scotland Yard did not name CNN presenter Morgan, it confirmed: “A 48-year-old man who is a journalist was interviewed under caution on December 6 2013 by officers from Operation Golding.”
It confirmed it was in connection with suspected conspiracy to intercept telephone voicemails and Morgan was not arrested.
Operation Golding is a part of Operation Weeting – specifically investigating allegations of phone interception at Mirror Group Newspapers.
Piers Morgan has his own CNN chat show since 2011, and presents an interview series for ITV as well as writing a column for the Mail on Sunday.
A CNN spokesperson said: “CNN has been aware of this interview since before it took place, and has no further comment.”