David Basi's lawyer, Michael Bolton, spoke to reporters outside the court Thursday morning. (CBC)

High-level B.C. government emails, possibly containing important evidence regarding the fraud and breach-of-trust trial linked to the $1-billion sale of BC Rail, may have been destroyed during the recent provincial election, according to lawyers for the accused.

For years, the lawyers for former government aides Dave Basi and Bob Virk have been asking for emails between members of the cabinet and senior staff to be handed over, saying they are critical to their clients' defence.

But a government lawyer said last month that executive-branch emails are kept for only 13 months. He told the court that is why emails between 2001 and 2005 are not available.

However, defence lawyers told reporters Thursday they have learned a company called EDS Advanced Solutions had many of these emails on backup tapes as recently as May.

According to an unconfirmed report published in the Globe and Mail newspaper Thursday, the government director in charge of managing the email delivery service filed an affidavit stating that during the May election campaign someone in authority asked that backup tapes of emails created before May 2004 be destroyed.

The affidavit was not released to the public. But according to the government's own guidelines, the emails should not have been deleted because of their relevance to the BC Rail corruption trial.

Court order sought

In B.C. Supreme Court on Thursday, Virk's lawyer, Kevin McCullough, asked Justice Elizabeth Bennett to issue a court order saying the government hasn't complied with orders to hand over all relevant material.

Bennett must now read 15 new affidavits, including statements from high-level political advisers like Martyn Brown, Premier Gordon Campbell's chief of staff, before she is expected to rule Monday on how to proceed.

Basi's lawyer, Michael Bolton, spoke to reporters outside the court Thursday morning.

"We are very concerned as to what happened. We really need the answers because this is very important evidence that could affect the outcome of this case," Bolton said.

Leonard Krog, the New Democrats' attorney general critic, called for the appointment of a special prosecutor to oversee an investigation.

"If this information is true, it amounts to not only a violation of government policy, but also a serious breach of trust and potential obstruction of justice," Krog said in a release.

"The investigation must determine who issued the order to destroy information and why the government turned its back on laws and policies that called for the retention of these records."

The charges of corruption and fraud against Basi and Virk stem from RCMP raids on the legislature in 2003. But the two aides have always maintained that whatever they did during the sale of BC Rail to CN Rail, it was on government orders.