Police fear a Brisbane father and his two young sons, who haven't been seen in over a week, may be stranded in an isolated part of outback Queensland. Stephen van Lonkhuyzen, 37, and his boys Ethan, 7, and Timothy, 5, vanished after starting out on a 1700km Christmas holiday road trip from Brisbane to Cairns. They left their home at Lota, in Brisbane's east, on December 11 and were expected to arrived in Cairns on December 15. But Mr Van Lonkhuyzon hasn't made contact with family and friends in over a week. The trio were last seen at a petrol station at Miles, northwest of Toowoomba, on December 11. Scroll down for video . Stephen van Lonkhuyzen, 37, (left) and his boys Ethan, 7, and Timothy, 5, (right) went missing on a road trip . 'Police hold concerns for their whereabouts as it is totally out of character for them not to make regular contact with family,' a spokesman said in a statement. Mr Lonkhuyzen last contacted his wife at Taroom on December 11 after he and his sons travelled inland to do some sightseeing. Detective Acting Superintendent Owen Elloy said Mr Van Lonkhuyzen may have decided to take his sons camping off-road and become stranded because of recent heavy rain. He said a massive search has been launched across a huge area of outback Queensland. 'We have had police, including those from Miles, Wondoan and Taroom, patrol hundreds of kilometres of outback roads, as well as camp grounds and truck stops,' he said. 'This is a vast geographical area that we are talking about and many roads are cut due to localised flooding or swollen creeks.' He urged property owners, station workers and motorists to keep an eye out for the trio. The family is travelling in a 1995 model white Mitsubishi Pajero, Queensland Registration 426 MCZ, and they are towing a silver trailer. The trio left Taroom on December 11  and were due to arrive in Cairns four days later but never did .
Stephen van Lonkhuyzen, 37, and his boys Ethan, 7, and Timothy, 5, left their home at Lota, in Brisbane's east, about midnight on December 11 .
The trio were due to arrive in Cairns on December 15 but never did .
They are travelling in a white Mitsubishi Pajero with registration 426MCZ and towing a trailer .
Police say many outback roads have been cut because of flooding and swollen creeks .
It is believed the car was last filled with fuel at Miles on December 11 .
Police fear a Brisbane father and his two young sons, who haven't been seen in over a week, may be stranded in an isolated part of outback Queensland. Stephen van Lonkhuyzen, 37, and his boys Ethan, 7, and Timothy, 5, vanished after starting out on a 1700km Christmas holiday road trip from Brisbane to Cairns. They left their home at Lota, in Brisbane's east, on December 11 and were expected to arrived in Cairns on December 15. But Mr Van Lonkhuyzon hasn't made contact with family and friends in over a week. The trio were last seen at a petrol station at Miles, northwest of Toowoomba, on December 11. Scroll down for video . Stephen van Lonkhuyzen, 37, (left) and his boys Ethan, 7, and Timothy, 5, (right) went missing on a road trip . 'Police hold concerns for their whereabouts as it is totally out of character for them not to make regular contact with family,' a spokesman said in a statement. Mr Lonkhuyzen last contacted his wife at Taroom on December 11 after he and his sons travelled inland to do some sightseeing. Detective Acting Superintendent Owen Elloy said Mr Van Lonkhuyzen may have decided to take his sons camping off-road and become stranded because of recent heavy rain. He said a massive search has been launched across a huge area of outback Queensland. 'We have had police, including those from Miles, Wondoan and Taroom, patrol hundreds of kilometres of outback roads, as well as camp grounds and truck stops,' he said. 'This is a vast geographical area that we are talking about and many roads are cut due to localised flooding or swollen creeks.' He urged property owners, station workers and motorists to keep an eye out for the trio. The family is travelling in a 1995 model white Mitsubishi Pajero, Queensland Registration 426 MCZ, and they are towing a silver trailer. The trio left Taroom on December 11  and were due to arrive in Cairns four days later but never did .
Queensland. Stephen van Lonkhuyzen, 37, and his home at Lota, in Brisbane's east, on December 11 37, (left) and his boys Ethan, 7, and Timothy, 5, and many roads are cut due to localised flooding for the trio. The family is travelling in a 1995 model white Mitsubishi Pajero, Queensland 11  and were due to arrive in Cairns four days later but never did .