Such borrowings must presumably date to the early Portuguese interception of the Pilbara coast, and indicate that the Portuguese did communicate with the Aboriginal people of the Pilbara coast.Again, however there is no evidence that the contacts were intensive or extensive enough to give rise to any contact language." Mühlhäusler agrees, stating that "von Brandenstein's evidence is quite unconvincing: his historical data is speculative - the colonisation being clandestine, there are no written records of it and his claims are not supported by the linguistic evidence he cites." In contemporary Australia, reports of textual and cartographic evidence, of varying significance, and occasionally artifacts are sometimes cited as likely to "rewrite" Australian History because they suggest a foreign presence in Australia.In 1895, George Collingridge produced his The Discovery of Australia, an attempt to trace all European efforts to find the Great Southern Land to the time of Cook, and also introducing his interpretation of the theory of Portuguese discovery of Australia, using the Dieppe maps.Fluent in Portuguese and Spanish, Collingridge was inspired by the publicity surrounding the arrival in Australia of copies of several Dieppe maps, which had been purchased by libraries in Melbourne, Adelaide and Sydney.Mc Intyre's book was reprinted in an abridged paperback edition in 1982 and again in 1987 In 1987, the Australian Minister for Science, Barry Jones, launching the Second Mahogany Ship Symposium in Warrnambool, said "I read Kenneth Mc Intyre's important book... In 1994, Mc Intyre expressed pleasure that his theory was gaining acceptance in Australia: "It is gradually seeping through. it has been on the school syllabus, and therefore students have... Speaking in 1982, Kenneth Mc Intyre described the Dieppe maps as "the only evidence of Portuguese discovery of Eastern Australia". In 1994, Mc Intyre suggested that the writings of Pedro Nunes supported his interpretation of the distortion that occurred on the Dieppe Maps.
This is based on the following elements: A group of mid-16th-century French maps, the Dieppe maps, formed his main evidence.
In 1899 he noted that the argument for the coasts of Australia having been reached early in the 16th century rested almost entirely on the supposition that at that time, "a certain unknown map-maker drew a large land, with indications of definite knowledge of its coasts, in the quarter of the globe in which Australia is placed".
He pointed out that "a difficulty arises from the necessity of supposing at least two separate voyages of discovery, one on each coast, though absolutely no record of any such exists".
1521–1524, one he argued had to be kept secret because of the 1494 Treaty of Tordesillas, which divided the undiscovered world into two halves for Portugal and Spain.
Barros and other Portuguese sources do not mention a discovery of land that could be Australia, but Mc Intyre conjectured this was because original documents were lost in the 1755 Lisbon earthquake, Most proponents of the theory of Portuguese discovery of Australia have supported Mc Intyre's hypothesis that it was Mendonça who sailed down the eastern Australian coast and provided charts which found their way onto the Dieppe maps, to be included as "Jave la Grande" in the 1540, 1550s and 1560s.