Government paid 10 times too much for land at Western Sydney airport to be used after 2050

Investigation found department's operations fell short of ethical standards' after land was valued at just $3.1m

Taxpayers stumped up $26.7m too much for land to build a second runway at Western Sydney airport after 2050, the auditor general has found.

In a scathing report, released on Monday, the Australian National Audit Office (ANAO) found the $30m price tag paid by the infrastructure department was almost 10 times its fair value.