ALGECIRAS (Agencies) Crimestoppers, the Northamptonshire police and the Spanish police authorities are seeking our help in detaining Anxiang Du, wanted for questioning in the murder of four members of the Ding family, the parents and two daughters aged 12 and 18, last April. The police suspect that the 53 year old may well be in the South of Spain or northern Morocco so the appeal for vigilance is aimed at users of the Algeciras-Tangier ferry, particularly during the summer crossing season (called Operación Paso del Estrecho), when passenger numbers multiply and it is easier for Anxiang Du to go unnoticed. Crimestoppers says that he should not be approached as he is considered very dangerous. There is a reward of up to £25,000 for information leading to his arrest. The Spanish phone number to report a sighting is 900 555 111, and the number in Britain is 0800 555 111.