We are not commenting on the specifics of evidence because it is an ongoing investigation.

We're not commenting on an ongoing legal proceeding.

He did voluntarily appear and give evidence as a witness in an ongoing homicide investigation.

All of that is part of the investigation, which is ongoing.

does not confirm if someone is a source or not, particularly in an ongoing investigation.

The president made it very clear, we're not going to comment on an ongoing investigation.