Action star Sylvester Stallone recently ran into trouble with authorities in Japan, after he was found in possession of growth hormones - according to his ex-fiancee Janice Dickinson. The former supermodel alleges Stallone was taken into custody after being caught with the same muscle-building drug he was convicted for possession of in Australia last February (07). Following that incident, he was formally convicted on charges of importing a prohibited substance in May (07) and was ordered to pay nearly $10,000 (GBP5,000) in fines and legal costs. And DICkinson claims Stallone is still up to no good. She tells the New York Post's gossip column Page Six, "Stallone was recently arrested in Japan for growth hormones." DICkinson recently revealed on a U.S. TV show that Stallone took the drugs to boost his body during their relationship in the early 1990s, and even claimed he once injected her in the arm when she was asleep - allegations Stallone has vehemently denied. But DICkinson is adamant she is telling the truth, and is demanding an apology for him branding her a 'liar'. And she has threatened to reveal all about the Rambo actor's past if he refuses to do as she asks. She adds, "If he doesn't shut his big mouth, I'm going to really tell everybody what he did to me. If he doesn't retract calling me a liar, I'm going to really talk - and he doesn't want that, so he'd better make nice..." The couple was engaged in the early 1990s, but Stallone ditched her when a DNA test proved he wasn't the father of her daughter Savannah. A representative for Stallone has declined to comment on DICkinson's latest allegations.