The trial of two Ross River men accused of violently sexually assaulting a woman in their community has been postponed, and more charges have been laid against one of the men.

William and Phillip Atkinson are charged with aggravated sexual assault and unlawful confinement in relation to an incident which occurred in October 2009, according to documents filed in Yukon Territorial Court.

The two men, aged 59 and 53 respectively, are both in custody at the Whitehorse Correctional Centre.

A number of phone calls made from the jail are at the root of the adjournment request, prosecutor Lee Kirkpatrick told the court during a hearing this morning.

William Atkinson now stands accused of making threatening phone calls from the jail to the complainant's sister, Kirkpatrick said. The official charges are obstruction of justice and uttering threats.

Three of the witnesses who were scheduled to testify during the trial, which was originally set for this week, have evidence to give on this new charge, Kirkpatrick said.

She noted that a cell phone had been confiscated as evidence from one of the witnesses and that investigators on the case are reviewing phone records from the jail.

Further complicating matters is the fact one of the two lawyers defending the men may also be called as a witness, Kirkpatrick added.

Gordon Coffin, a legal aid lawyer, is representing Phillip Atkinson; while Keith Parkkari, a partner in the firm Austring, Fendrick, Fairman and Parkkari, is acting for William Atkinson.

Kirkpatrick did not say which of the two defence lawyers may be called as a witness.

Judge John Faulkner adjourned the matter, with Kirkpatrick indicating the trial will likely be rescheduled for May.

The complainant's sister was added to a list of people the two men are barred from contacting, directly or indirectly.