The battle between coronary device maker Boston Scientific (NYSE:BSX) and Medinol Ltd. is heating up as the U.S. firm on Monday responded to a lawsuit from its stent supplier and acquisition target, Medinol, with a counter suit. Boston Scientific is suing Medinol for alleged fraud and breach of contract. It is also seeking an injunction to prevent its Israeli supplier from offering its technology to competitors.

This comes after months of talks during which Boston Scientific tried to acquire Medinol, and after a lawsuit filed by Medinol against Boston Scientific.

Medinol, which makes metal mesh tubes called stents used to prop open major heart vessels unclogged by surgery, first filed suit against Boston Scientific on April 6th of this year. It claimed that Boston Scientific had misappropriated intellectual property and submitted fraudulent filings to the U.S. Food and Drug Administration in order to steal Medinol's business.

Over the past weekend, the Israeli stent-maker expanded its suit against Boston Scientific. Medinol claims that the Express stent Boston Scientific presented as its own independent development copies structural principles of Medinol's Nir stent line, the Nirflex. Medinol claims that Boston is violating its patent.

Boston claims that it did not misappropriate its partner's technology.

In its suit filed on Monday in the U.S. District Court for the Southern District of New York, Boston Scientific has charged Medinol and its principals, Judith and Jacob Richter, with multiple breaches of contract, unfair and deceptive practices, and defamation.

Boston Scientific said in a statement it is asking the court to order Medinol to grant a fully paid, perpetual and exclusive license to manufacture and distribute all Nir stents, and to pay compensatory punitive and multiple damages.

Boston Scientific claims that Medinol did not honor an agreement to design, build and make operational an independent manufacturing line at Boston Scientific, in the event that it could not or would not provide the company with stents.

As recently as April 11, Boston Scientific said that it still hoped to acquire Medinol.