Daughter of the slain German developer is determined to have the killers brought to justice The family of murdered German property developer Anton Forstenhausler yesterday told of their grief and vowed to 'leave no stone unturned' in bringing the killers to justice. 'Our utmost priority is to bring to justice the people who are responsible for this most heinous crime,' a family statement released by his daughter Mirjam said. 'The family will stop at nothing to arrive at the truth,' it said. Forstenhausler, 69, Swiss millionaire Manfred Schoeni, 58, Hong Kong architect John Cowperthwaite, 62, and domestic helper Irma Sarmiento were found hacked to death in the German's three-storey luxury villa on the resort island of Boracay on Monday. Eleven construction workers are still being questioned by police. No charges have been laid. 'The violent and gruesome manner by which he and the other three victims were killed deserves the strongest possible condemnation,' the statement said. 'There are no words to express the grief of the family ... over his untimely demise and our sympathy for the families of the other victims.' His daughter, a former Hong Kong resident who now lives in London, flew out of Boracay yesterday after meeting officials working on the high-profile murder which has attracted world-wide attention. She said she was deeply traumatised by the brutal and 'senseless' slaying of her father and his friends. 'Our beloved Anton was a kind, honest and generous man, a loving husband and father. 'He will truly be missed by everyone close to him.' The family said they had been overwhelmed by the outpouring of support from friends and members of his adopted community in Boracay. The former Hong Kong businessman and international hotelier had recently sold one of the sites at his luxury villa development to close friend Schoeni, a multi-millionaire and one of Asia's best-known art dealers. Schoeni and prominent architect Cowperthwaite, the son of former Hong Kong financial secretary Sir John Cowperthwaite, were on the island to discuss plans for the hilltop site. The family said they wanted to thank the officials who had been 'working around the clock' to expedite the murder investigation. Forstenhausler's neighbour Julius Varga, who was among the last to see him alive, said the German developer had few visitors, rarely went out and was not the type to party. Mr Varga said Forstenhausler had lavished money on building his villa. He had mostly imported materials to build the home and had paid attention to the most minute of details, supervising the construction workers thoroughly. He said Forstenhausler had been very strong for a man his age. 'I've seen him carry a sack of sand,' Mr Varga said. The neighbour said the German developer had had some cash-flow problems and would ask for a cash advance to help pay for sacks of cement that were about to be delivered.