The pair’s claim came as the military inspected the alleged site in south-west Poland.
Identifying themselves as Andreas Richter and Piotr Koper, the men appeared on TVP.INFO.
Authorities in the city of Walbrzych said last month two men had contacted them through lawyers claiming they had found an armoured train that possibly contains valuables and weapons.
The report sparked a gold rush around Walbrzych, where tales have circulated since the Second World War that the Nazis hid a train full of gold from the Soviet Army in early 1945.
“As the finders of a World War Two armoured train, we, Andreas Richter and Piotr Koper, declare that we have legally informed state authorities about the find and have precisely indicated the location in the presence of Walbrzych authorities and the police,” Mr Koper said, reading a statement on TV with Mr Richter at his side.
“We have irrefutable proof of its existence.”
Their knowledge is based on information from witnesses, and research carried out with their own equipment, Mr Koper said.
TVP.INFO said the train is not in a tunnel, as previously believed, but buried in the ground. Mr Koper said the two men are ready to cover the costs of the train’s retrieval and want it to become a tourist attraction.
TV cameras showed Polish military officials checking the purported site in the woods, which police are patrolling to keep swarms of treasure hunters from digging it up.
The placid woodlands around the medieval castle town have suddenly become the hottest spot in Poland — as treasure hunters descend in search of the mystery Nazi train said to be laden with gold.
Rumours have swirled for decades about the gold train, though there is no evidence that it ever existed.
A government official said last week the claimants’ theory is based on the “deathbed testimony” of one of the men who allegedly helped load the train at the end of the war. If the train eventually does turn up, it will belong to the Polish state.
The two claimants are demanding 10% of the value of the find, which officials have said they will get. Serious excavation work is expected to start within weeks.