Lord of the Rings director Peter Jackson said both Sorvino and Ashley Judd were "blacklisted" following conversations with Weinstein's company.
Both actresses have claimed the media mogul sexually harassed them.
Weinstein has denied allegations of misconduct, and of blacklisting the actresses.
The Lord of the Rings trilogy was initially in development with Weinstein's Miramax company, before being passed to New Line Cinema.
In an interview with Stuff.co.nz this week, Jackson said he was interested in casting both women in the blockbuster franchise.
"I recall Miramax telling us they were a nightmare to work with and we should avoid them at all costs. This was probably in 1998," he told the site.
"At the time, we had no reason to question what these guys were telling us."
"I now suspect we were fed false information about both of these talented women - and as a direct result their names were removed from our casting list."
"In hindsight, I realise that this was very likely the Miramax smear campaign in full swing," Jackson said.
Sorvino said in a tweet: "Just seeing this after I awoke, I burst out crying."
"There it is, confirmation that Harvey Weinstein derailed my career, something I suspected but was unsure. Thank you Peter Jackson for being honest. I'm just heartsick."
Judd, meanwhile, recalled how her involvement progressed far enough to be invited by Jackson to see preparation work for the blockbuster trilogy.
"I remember this well," she tweeted.
"They asked which if the two roles I preferred, and then I abruptly never heard from them again. I appreciate the truth coming out," she said.
n a statement through a publicist, Weinstein denied the allegations that he was involved in blacklisting Sorvino and Judd, saying that the casting for Lord of the Rings was carried out by New Line Cinema - not Miramax.
The statement said that Judd was cast in two other films by Mr Weinstein, and that "Sorvino was always considered for other films as well."