AIM-listed coal miner Churchill Mining reported a widening of losses in the first half and said that a continued court case in Indonesia will carry on for several months, causing shares to lose over a fifth of their value on Tuesday.The group also announced that it would be putting aside $140,000 in anticipation of a potential fine after it was accused of breaching listing rules by the London Stock Exchange, though it said it would be defending disciplinary action. The company said it has been accused of breaking AIM rules over four years ago.The group, which has yet to generate any revenue, reported a loss for the six months to 31 December of $1.06m, compared with $0.90m the year before.The deterioration came as foreign exchange losses ballooned to $123,826 from $5,411, reflecting the weakening of the pound and the Australian dollar against the US dollar in cash accounts.Churchill is currently engaged in an international arbitration against the Indonesian government in relation to the revocation of mining licences that made up the East Kutai Coal Project in East Kalimantan in which it held a 75% stake.The company has been accused of forging original documents relating to the mining licenses but has denied this claim. In August last year, police officers raided its Jakarta office and seized a number of documents on the same day a court-ordered document inspection was to take place."It remains the company's view that this police raid was strategically timed to harm and prejudice the Company's case currently being heard by the Tribunal," Churchill said.The group announced on Tuesday that the next document authenticity hearing will not be held until the first week of August 2015.By 16:03 on Tuesday, the stock was down 20.8% at 10.3p.