"Invariably we'd come home and she'd go 'no, no. I've read it, read it, read it'," he laughs.
"More often than not we'd have to go back up to the library and get more books. I've never seen anyone read as much as her. She was an amazing lady."
And she was just as avid with her mysteries on the television.
"She'd say 'it's the only thing I watch a week'," he says.
"Well, the only thing she seemed to watch a week, seemed to be quite a few of them."
Wenham says as well as reminding him of his late mum, he wanted to take on the project just because it looked fun.
"It's just an enjoyable thing, that's not going to fry my brain and I'm not going to have an emotional breakdown getting the character together," he says.
His character in the telemovie is the proficient, if jaded, Detective Bennett O'Mara.
"He's very, very good at his job," Wenham explains.
"He's detoxing when we first meet him and that seems to suggest that there has been something different in his life. We find out during the movie what that is."
His onscreen love interest, chocolate shop owner Juliana Lovece, played by British actress Louise Lombard, is the exact opposite.
She's innocent but not naive and despite having gone through a nasty divorce isn't distrustful.
"After everything that's happened to her she could have become bitter or cynical but she hasn't," Lombard says.
"She's a light spirit and I like that."
Lombard says she liked the fact that the role was a big departure from the many detective roles she's played.
"Usually that's the sort of role I get cast in so it was a welcome change to get cast as someone who's the innocent," she says.
"There's also something quite old-fashioned about the pace of the piece that I was drawn to too."
Playing someone who works with chocolate was also too hard to resist, says Lombard.
"It just says so much about a person who chooses to make chocolate their life," she says.
As you would expect from someone whose occupation is chocolate, her character cannot understand why Bennett would choose to go on a detox.
"Essentially it's depriving yourself," Lombard says.
"There's nothing wrong with giving yourself what you desire."
The actress says she liked the relationship between Juliana and Bennett because it reflected the life experiences of many people in their 30s and 40s.
"If you're this age and haven't had a relationship that has had issues, or has gone badly, or ended badly or you've done the wrong thing, then it's quite unusual," she says.
"Everybody has. I think the characters are very relatable."
Who: David Wenham and Louise Lombard
What: Detective romance drama Dripping in Chocolate which also stars Chelsea Preston-Crayford
When and where: UKTV, Sunday April 8, 7pm as part of the channel's Easter Whodunnit Weekend
- AAP
