Kat (Jessie Wallace) has been cheating on husband Alfie (Shane Richie) with an unknown man in recent weeks, and Venn's character Ray Dixon is one of five suspects in the frame.
Speaking on Daybreak today (August 1), Venn explained that the EastEnders cast and crew are still in the dark over the story's outcome.
Pictured: Chucky Venn on Daybreak.
Discussing whether Ray could be the man in question, Venn commented: "Your guess is as good as mine - I have no idea. It's all strictly confidential. No-one knows, honestly. It's all very, very underhand right now."
Asked whether it is difficult to film scenes with so little information, he replied: "No, not for me personally. I play what's on the paper - I'm in the moment. So as far as I'm concerned, until I know otherwise, I'm playing what I see - straight up. That's the best way, don't pre-empt anything.
"It's a lot of fun. Of course it's all very cloak and dagger at the moment and we're just enjoying the moment, we're enjoying the hype, all the secrecy. It's all very clandestine at the moment."
Venn also predicted that Ray's girlfriend Kim Fox (Tameka Empson) would have an explosive reaction if it turned out that he had cheated on her.
He said: "I would love it to be me - for the drama, of course. Why not? You can just imagine the kind of drama which would ensue with Kim. It'd be fight of the century, that one. Dynasty would have nothing on this!"
EastEnders continues tomorrow (August 2) at 7.30pm on BBC Two. Get the Inside Soap magazine on your iPhone or iPad