A Far North man was tied up and injured by three men who police say burst into his home early yesterday. Scientists from Environmental Science and Research in Auckland were at the rural home at Waiharara, 24km north-west of Kaitaia, collecting evidence and searching a nearby business. Kaitaia police Senior Sergeant GordonGunn said the invasion and aggravated robbery happened shortly after midnight. Police were alerted after the intruders left and the victim managed to free himself. The victim, in his 50s, was alone in the house when the trio arrived. Mr Gunn was unable to say how the man was injured, but said there was blood at the house where he was bound. "Things are still unfolding. The victim has been interviewed and we are piecing it together," Mr Gunn said. A car was found burnt out in a ditch halfway between Waiharara and Ahipara, and police believe it may have been used in the attack. It was taken to Kaitaia police station and was to undergo an examination by ESR scientists.