The acknowledgement came several weeks after Mitsubishi Heavy Industries, confirming that scores of its servers and PCs had been infected, .

Previously, a U.S.-based Mitsubishi Heavy spokesman had said that although attackers had uncovered company IP (Internet Protocol) addresses, the attack "was caught at an early stage."

But yesterday the company changed its tune, saying that more investigation had revealed a possible loss of information.

"The company recently confirmed unintended transferring of some information on the company's products and technologies between servers within the company," said Mitsubishi Heavy in a . "Based on the finding, the company investigated the incident further and recognized the possibility of some data leakage from the server in question."

The company declined to confirm that any diversion of data related to defense or nuclear technologies took place.