The Canadian school teacher died on August 18, 2010, while the couple were boating in a small inflatable vessel.
Her death was initially reported as a drowning, Beckett claiming she accidentally fell from the boat, but he was arrested a year after she died and sentenced to 25 years' imprisonment without possibility of parole.
Beckett formerly ran a tour business taking groups from Napier to Cape Kidnappers, before he became a Napier councillor in 1998.
He served one term between 1998 and 2001 and then moved to Canada, where he met and married Letts.
Ighani is also accused of stabbing David James McHale, 70, who is serving time after pleading guilty to three counts of sexual interference in Kelowna in April 2017.
McHale filed a lawsuit against the B.C. Government claiming a guard was partly responsible for the attack because the guard failed to lock a gate on the protective custody unit, where the stabbings are said to have occurred.
Security concerns have prompted a judge to allow one of two men to testify by video at the preliminary inquiry.
Judge Greg Koturbash granted the application for video testimony after hearing previously from the Crown about logistical problems sheriffs would have at the cramped Penticton courthouse ensuring the safety of the three men involved, all of whom are incarcerated.
Separate charges against Ighani, including kidnapping, assault and firearms charges related to an alleged crime spree last year, are set to go to trial June 4 in B.C. Supreme Court in Penticton.
Ighani's lengthy criminal record resulted in him twice being ordered deported from Canada.
However, he successfully appealed that order in 2002, and it is reported that Canada did not send him back to his native Iran to face the death penalty in 2007.
- Additional reporting by the Penticton Herald.
