Bondholders and a key shareholder in George Economou-led Ocean Rig are lashing out at the drilling contractor for the circumstances leading up to its insolvency proceedings in the Cayman Islands, and one says it is planning to take the fight directly to Economou and DryShips.

Creditor and shareholder Highland Capital Management is threatening to take legal action against the Greek shipping mogul and his Nasdaq-listed shipowning company, which had been Ocean Rig’s majority shareholder before selling out last April, by targeting the controversial use of related-party transactions that are common to both Economou-led companies.

Separately,