How often does Grewal tape conversations?

In the article cited below (here), Grewal makes an off-hand comment that is, frankly, pretty stunning. Referring to negotiations to resolve a battle for a Liberal nomination in the BC provincial election of 1995 (which Grewal claims he was bribed to give up)

Grewal then went to the media, claiming publicly Sandy Powar, the B.C. Liberal party secretary, tried prior to that meeting to bribe him by saying he could be named a deputy minister in a Campbell government if he stepped aside. Grewal said he believes he still might have a tape of that conversation.

There is surely a disturbing pattern emerging here: secret negotiations, disputed versions of the events, accusations that his opponents are lying, and the taping of conversations.

The troubling question is how many other conversations has Grewal taped?