The 27-year-old, who clashed with Sugden both inside and outside of the house, has allegedly recruited Jonathan Coad, the lawyer who represented Tulisa Contostavlos during her sex tape scandal, and contacted police following the leak.
Lennard's suspicions apparently stem from Sugden commenting on the Twitter profile of Page 3 girl Kelly Hall when she published the image last night in a now-deleted message.
"Well.. Thankyou to @kellyhallmodel for her last tweet," Sugden wrote. "No words needed.. *smirks*."
A spokesperson for Lennard told the Mail Online: "Jasmine believes that Rhian was behind or in someway involved in the leaking of the picture.
"Jasmine is incredibly disappointed but this is entirely characteristic of Rhian."
Sugden has since defended herself against suggestions that she was picking on Lennard with her tweet.
"Hear I'm being called a bully??" she wrote. "Can someone show me on my page where I've bullied anyone? #hypocrite #boringnow #moveon *rolls eyes*."
Lennard famously described Sugden and their CBB co-star Danica Thrall as "skanky girls" during her live post-eviction interview, while the 25-year-old branded Simon Cowell's ex "psychotic" and claimed she was "scared to death" of her in the house.