Defence lawyers continued their questioning of an undercover officer who befriended the three men accused in Nadia Gehl's murder on Tuesday.

Gehl's husband Ronald Cyr, Nashat Qahwash and Zdenek ‘Dennis' Zvolensky each face a first degree murder charge in the February 2009 shooting death.

The officer, known only as UCJ, was grilled by Qahwash's lawyer last week, and on Tuesday Zvolensky's attorney continued the questioning.

UCJ has testified that all of the accused implicated themselves in the crime and Zvolensky and Cyr were heard admitting to their involvement in recordings played for the court.

But the defence is trying to poke holes in UCJ's testimony.

Zvolensky's lawyer claims his client was a ‘motor-mouth' who was attempting to fool the officer in the same way UCJ was fooling the three accused.

The officer disagreed with that assessment, however.

Zvolensky's DNA was found on the murder weapon, and the court has heard Zvolensky say he was willing to take care of UCJ's problematic, but fictitious ex-wife.

UCJ had implied there were concerns she would scuttle plans for the group to buy a canoeing business together.