just out of interest spoken
as a matter of interest spoken

Health care was hardly his strong point, or even a matter of major interest to him.

By 1900, the discussion had become a matter of public interest.

But this is not just a matter of historical interest.

That was quite clearly a matter of great public interest and concern.

Just as a matter of interest, when did he last ask you to go away with him?

When he brought up the issue in court two weeks ago, the judge said it was a matter of public interest.

Between 1977 and 2004 all the member were, to be sure, not each other, but kept a matter of interest in music.

As a matter of interest, why did you stick with your union for 33 years?

He turned his attention back to matters of public interest.

You will certainly understand that this is, in a certain way, a matter of interest to Members.