Police launched fresh raids Friday in connection with the failed terrorist plot in Britain, seizing computer files and other material from two hospitals in western Australia, the federal police chief said. Australian Federal Police Commissioner Mick Keelty said computers were seized from hospitals in the Western Australia state capital of Perth and the Outback mining town of Kalgoorlie in the same state. There have been no further arrests since Indian doctor Muhammad Haneef, 27, was detained Monday at the international airport in the eastern city of Brisbane as he tried to board a flight with a one-way ticket. A judge late Thursday granted police permission to hold Haneef without charge for another four days. Keelty, who is overseeing an Australian investigation on behalf of the British counterterror inquiry, said several doctors in Western Australia of Indian background with experience in the British health system had been interviewed. Another doctor also had been interviewed Friday in New South Wales state, he said. That physician was of Indian descent and based in Sydney, Australia's largest city, Ten Network television reported. "There are a number of people now being interviewed as part of this investigation; it doesn't mean that they're all suspects but it is quite a complex investigation and the links to the UK are becoming more concrete," Keelty told reporters in Canberra, the national capital. The questioning Friday was "to gather evidence or gather information about the network, about who is linked to who, and who, if in fact if anybody, has committed any criminal offense," he said. The seized computers had been used to communicate with Haneef, Keelty said. Haneef, who moved from the United Kingdom last year to take a hospital job in Gold Coast city in Queensland, is related to one of seven suspects in custody Britain, Saleeb Ahmed. The pair worked together at Halton Hospital in northern England in 2005. Keelty said search warrants were executed at two others premises in Western Australia, which he did not identify. Medical officials said Thursday that Ahmed, 26, and a second suspect in the British plot, Lebanese doctor Khalid Ahmed, 27, had unsuccessfully applied for medical jobs in the Western Australia public hospital system in the past two years. State police, working with their federal counterparts, had interviewed four men overnight in connection with the investigation, seizing computers and communication equipment, state Police Deputy Commissioner Murray Lampard said.