Risco is alleging mismanagement and excessive spending while Tap is suggesting that the shareholder is in breach of sections of the Corporations Act with an undisclosed association with another of Tap's major shareholders.
Tap says that Risco and major Thai businessman Chatchai Yenbamtoong, who owns 22.56% of the Aussie junior, through his own interest and holdings in Northern Gulf Petroleum Holdings, have become associated in contravention of sections of Corporations Act.
Tap also says Risco has failed to disclose the ultimate controller of its Tap shares in that it has not disclosed in substantial holder notices that Suncastle Equities has a relevant interest in its Tap shares.
Risco has a 22.1% interest in Tap, which now seeks an interim order that Risco disclose the interests of its ultimate controller of its Tap shares and that Tap's major shareholders both disclose their association and also be restrained from exercising their voting rights regarding their plans for director changes.
Tap is is also seeking orders from the Takeovers Panel that its major shareholders lodge corrective substantial holder notices disclosing their association and a final order to the effect that shares in which Tap's major shareholders have relevant interests exceeding 20% be vested in Australian Securities and Investment Corporation.
Yesterday Risco announced it wished to throw out three Tap directors to replace them with its own picks, listing a series of grievances on expenditure and loss of share price that sound very similar to those aired by Mr Yenbamtoong in 2015, when he tried to dislodge two Tap directors for four of his own men and complained loudly of shareholder losses and poor management.
Risco co-founder Tom Soulsby, who is on the Tap board, has said it's time for his fellow board members executive chairman James Menzies and independent director Peter Mansell to go, and he plans to exit with them to make way for Risco's other founder Chris Newton.
Menzies and Mansell would be replaced by ex-Sun Resources boss Govert van Ek, whose recent history includes co-founding a blockchain company.
"The business strategy outlined at Tap's annual general meeting earlier in February this year has failed to deliver," Soulsby said.
"Since that time, despite a new business development team being installed, no deals have been secured."
"Over the same interval, Tap's share price has fallen from 9c to as low as5c a 30% decline and is now about 6c. This leaves Tap a a bottom quartile performer against its peers."
Soulsby says that Risco has taken a balanced and commercial view of things given administration costs are "excessively high" at $500,000 a year.
Tap board costs are close to $500,000 annually, and Risco says the junior's board is not fit for purpose for a company with a market capitalisation of about $25 million and the company needs a "more robust and less speculative business strategy".
Tap should focus on its producing asset, a 30% share in the G1/48 concession in the Gulf of Thailand which includes the producing Manora oil field.
Risco steadfastly maintains it has not breached the Corporations Act in any way and that Tap's allegations, which it first aired last week in a letter to shareholders, are inaccurate and based on second- or third-hand information.
Tap is trading at 5.9c.