A newly filed racketeering lawsuit claims several law firms, including K&L Gates and BCL Burton Copeland, were key participants in an alleged scheme to cover up widespread sexual misconduct by disgraced Hollywood producer Harvey Weinstein.

Six women, represented by US law firm Hagens Berman Sobol Shapiro, have filed a proposed class action in Manhattan federal court, accusing Weinstein, the Weinstein Company, the company's board members, Miramax and others, of violating the Racketeer Influenced and Corrupt Organizations (RICO) Act.

The complaint parallels a similar one filed last month in California, with both complaints alleging that advisers and others in Weinstein's orbit – referred as members of a "Weinstein Sexual Enterprise" – helped "facilitate and conceal" a pattern of unwanted sexual conduct perpetrated by the film producer.

Prominent litigator David Boies and his law firm Boies Schiller Flexner had already been in the public spotlight over his work for Weinstein following a New Yorker report that the lawyer contracted with an Israeli private intelligence agency, Black Cube, as it was trying to derail a potential New York Times story about Weinstein's predatory behaviour toward women. That scrutiny continued this week when Boies' actions came up again in a lengthy New York Times article looking at people who helped Weinstein keep his misconduct under wraps.

But the successive RICO suits also suggest that the fallout from the Weinstein scandal is expanding to include other legal advisers.

Although it does not specifically name lawyers or law firms as defendants, the complaint casts the lawyers and law firms surrounding Weinstein – including Boies Schiller, K&L Gates, London corporate crime firm BCL Burton Copeland and Israel's Gross Kleinhendler Hodak Halevy Greenberg & Co – as central figures in the alleged scheme to cover up his misconduct.

The firms are described as "co-conspirators" along with others that included Weinstein's business associates and private intelligence firms.

"The law firm participants provided cover and shield to the Weinstein participants by contracting with the intelligence participants on behalf of the Weinstein participants and permitting the Weinstein participants to protect evidence of Weinstein's misconduct under the guise of the attorney-client privilege or the doctrine of attorney work product when that was not the case," the complaint said. "The law firm participants also approved the intelligence participants' 'operational methodologies', which were illegal."

In an emailed statement on Thursday, K&L Gates described the complaint's allegations about the firm as untrue and denied that it ever worked for Weinstein.

"We are aware of the lawsuits filed against Harvey Weinstein and others that mention K&L Gates. K&L Gates is not named as a defendant in the lawsuits but the suits attempt to claim that the firm was involved in a scheme to facilitate or cover up Mr Weinstein's activities. The claims relating to K&L Gates are false. K&L Gates has never represented Mr Weinstein or any other person or entity concerning investigations or inquiries relating to Mr Weinstein," the firm's statement said.

Representatives for the other law firms did not immediately respond to requests for comment. Previously, Boies Schiller provided a statement to Legal Week US sister title The Recorder indicating that it would refrain from commenting on Weinstein-related matters in connection with a request from the producer's current defence lawyer, Benjamin Brafman.

Last week, Fieldfisher filed a UK civil claim against Weinstein on behalf of a client who alleges they were sexually assaulted by the producer. The claim has been made against against Weinstein himself and the Weinstein Company's UK and US arms, asserting that the movie producer's company is "vicariously liable" for his alleged assaults.