The hunt for two missing brothers, last seen in a car with their father almost a week ago, has moved to the area around a fishing lake in Geulle, Limburg.

Police began searching the area on Sunday and are resuming their efforts to find Ruben, 9, and Julian, 7, on Monday. According to the Telegraaf, international experts including FBI-trained behavioural analyst Carlo Schippers have been brought in to help.

The paper says it is becoming increasingly apparent that the boys’ father left as few traces as possible to make it difficult to find the children. He hung himself in woods near Utrecht on Tuesday morning.

Police have also appealed for information about the father’s walking boots which were not found with his body.