A US short-selling specialist laughed off the possibility the news from embattled hospital operator NMC Health PLC (LON:NMC) that it had received two preliminary bid approaches. 

Abu Dhabi-based NMC said on Monday morning that it had received a pair of “highly preliminary” approaches from US private equity firms KKR and GKI.

READ: NMC Health confirms approaches but ownership waters muddied

NMC’s share price been in free-fall since hedge fund Muddy Waters trained its sights on the FTSE 100-listed group in mid-December, with a comprehensive report that voiced concerns about NMC financial statements.

After Muddy Water’s critical assessment was publicly disseminated, along with the news that the hedge fund had taken a short position in the shares, the shares have plunged more than 70%, forcing major shareholders to sell stock to cover margin calls.  

With reports that NMC’s founder is mulling a return and the company mentioning names of some of the private equity interest that has been said to be circling, Muddy Waters founder Carson Block issued a dismissive response.

“Today’s bizarre disclosures about even more pledges and debt validate that the cockroach theory is alive and well – what we found is likely just the tip of the iceberg,” Block said in a statement. 

“As for the notion that NMC might receive private equity bids, it’s hard for us to believe they would survive due diligence.”

NMC shares were up 5% to 738.8p by Monday afternoon.