Hackers linked to the Chinese government have broken into the computers of airlines and military companies more than 20 times in a year, according to the US Senate.
The attacks targeted systems that transport troops and equipment.
They also targeted a commercial ship and loaded malicious software onto the computers of an airline, the Senate reports.
The Chinese officials denied the allegations.
The investigation that lasted a full year was completed in March, but the findings have only just been made public.
Over a 12-month period, from June 2012, evidence of approximately 50 cyber-attacks on military companies was found.
Of these, 20 were attributed to «advanced persistent threat», a term associated with attacks on governments originating from China.
The report does not reveal the names of the organizations that are affected.
Chinese officials at the embassy in Washington disputed the report, describing the allegations «baseless».
The case of cyber attacks between China and the US is long-standing.
The Chinese government has already accused US spies of infiltrating its computer networks.
In May, the US government charged five members of the Chinese with hacking systems and stealing trade secrets from the computers of several major American companies.
The latest report revealed that the representatives knew only about two of these incidents. It was also found that US government offices failed to share information regarding the attacks among themselves.
This lack of transparency from organizations has raised questions and has prompted calls for new procedures regarding how these hacks are recorded.
