Richard Mehan’s shock departure from the chief executive role at Brian Gilbertson-chaired iron ore and manganese explorer Jupiter Mines last week set tongues wagging in the industry, with further speculation rife after the company said it had rejected an approach about selling one of its assets.

Jupiter’s current partner in the Tshipi manganese project in South Africa, OM Holdings , had planned to buy a 49.9 per cent stake from Gilbertson’s Pallinghurst Investments in 2010, but the two could never agree on terms.