Hologic (NSDQ:HOLX) has already been through its fair share of legal action from its acquisition of Interlace Medical, which it acquired for $125 million in 2011.

Bedford, Mass.-based Hologic lost a patent infringement lawsuit to rival Smith & Nephew (FTSE:SN, NYSE:SNN) last year over the MyoSure fibroid device it bought along with Interlace.

Last month Hologic asked a federal judge in Massachusetts to revisit that loss. A jury had awarded $4 million in damages in September 2012 to cover Smith & Nephew’s lost profits from the infringement. In June, Judge Rya Zobel of the U.S. District Court for Massachusetts upheld that decision but found that any damages owed by Hologic to the British medical products giant couldn’t yet be determined.

Now, some of Interlace’s shareholders are suing for more cash, according to a regulatory filing.

"On October 29, 2013, the Interlace stockholder representatives filed a complaint in the Delaware Court of Chancery alleging breach of contract for issues related to the payment of contingent consideration under the Interlace merger and acquisition agreement, and are seeking $14.7 million in additional payments," according to the filing. "The company believes that Interlace has been paid all amounts due under the merger agreement and their claims are without merit."

The 1st Smith & Nephew lawsuit, filed against Interlace in 2010, accused its chief technology officer Ronald Adams, an SNN employee from 2002 to 2006, of bringing the technology with him when he jumped ship for the then-startup. Smith & Nephew sued Hologic, along similar grounds, after its Interlace buyout.

Interlace won 510(k) clearance for the device in October 2009, raising $21 million in June 2010 in a Series C round aimed at commercializing the MyoSure system. The company also won a $75,000 tax break from the Mass. Life Sciences Center to foster the creation of 10 permanent life science jobs in the Bay State. In 2009, Interlace landed a $300,000 tax break from the Commonwealth.