He is expected to apply for bail when he appears before Gibraltar magistrates next week. Mr Newall, 27, a former lieutenant in the Royal Green Jackets, is accused of murdering Nicholas and Elizabeth Newall, who were last seen alive in Jersey in October 1987.
Jersey's Attorney General, Philip Bailhache QC, the island's chief prosecutor, is preparing the case against Mr Newall. It is the first time Jersey has sought to extradite a suspect from Gibraltar and there are fears that if contested the proceedings could take months to complete.
Mr Newall's lawyers said he had been openly visiting relatives in Britain and trying to buy a new boat before sailing to the south Atlantic to set up a chartering business.
Mr Newall is being represented by Christopher Finch, the Gibraltar lawyer who advised Thames TV on the making of its 1988 documentary, Death On The Rock, which investigated the SAS shooting of IRA terrorists on the rock.