TODAY | June 19, 2013
>>> in the search for the remains of jimmy hoffa 38 years after his disappearance. katie is in oakland township . good morning.
>> reporter: dpoorng. what started out as a promising day yesterday, nothing. still investigators are hopeful that this latest most credible tip will finally be the one. investigators will be back at it this morning after what they call an important day. they have been searching on their hands and knees sifting through piles of earth. at first glance it looked more like an archaeological dig than a potential crime scene but by midday, small signs of hope as a cadaver dog hit on some remains.
>> the cadaver dog worked the area and reacted to some scent but we wouldn't call it conclusive.
>> still it was in an area that investigators say they'll be checking again.
>> i know he's there.
>> the fbi was lead to this site by tony, the son of a detroit mob boss and alleged to have been an underboss himself. he was told after hoffa's disappearance he was taken to a barn on this field, hit in the head with a shovel, buried alive in a shallow grave and covered with cement.
>> they have been searching for two days and they haven't found anything yet. you're sure he's there.
>> no question in my mind. i'm not wrong. you can bet on it.
>> reporter: a number of concrete slabs were discovered in the field, so far consistent with at least part of the story. and after 38 years, former detroit fbi special agent in charge , andrew arena says the agency has to keep following leads.
>> if it was your father, it was your brother, your son, would you want them looking or would you want them just to give up?
>> reporter: a law enforcement source tells me that the remains the dog hit yesterday were definitely not human and although investigators are hopeful there's growing concern if they don't find hoffa here off of this tip, they may never find him.