Seems to be based on nothing more than Warnock's pre-Saints press conference, in which case it is pure guesswork. Nothing Warnock said confirms that a bid has been made (yet).
I can't see us spending 25m on a striker that's 28, has had 4 good months in his career and is out of contract in 18 months.
Having said that, we spent 6m on Madine who is basically a carbon copy in terms of a purple patch.