Rome, August 23 - The Italian government on Friday vowed to continue to work towards a "swift and fair" solution to the case of two Italian marines accused of killing two Indian fishermen while on anti-piracy duty last year. The third meeting of the government's working group on the case, with Premier Enrico Letta, foreign, justice and defence ministers, and envoy Staffan de Mistura, said it was awaiting the completion of an Indian probe ahead of trial. One final legal opinion on witness interviews is the sole roadblock to wrapping up the probe, India said this week. Indian Foreign Minister Salman Khurshid said Thursday the government's lawyers had found a solution to the testifying issue, although he said he preferred to wait for the lawyers to announced it. The four witnesses - fellow marines who are thought to have seen what happened the night two of their comrades allegedly killed the two Indian fishermen - are at the heart of a dispute over whether they should be in India for interviews by investigators. Italy maintains their presence is not necessary to the investigation of Salvatore Girone and Massimiliano Latorre, accused of murder in the shooting deaths of two fishermen in February 2012. The pair allegedly mistook the fishermen for pirates. The four witnesses could be interviewed long-distance, Italian authorities have said. Italian Defence Minister Mario Mauro said the witnesses could be interviewed by video conference or by Indian investigators on Italian soil.