There were some lively exchanges Friday when Conservative Sen. Dave Tkachuk was interviewed by the CBC's Sheila Coles about the senate expense scandal.

Among the topics: a new CBC report about embattled Sen. Mike Duffy apparently angling for a cabinet position, along with extra perks.

"Oh my ... it never ends," said Tkachuk, who himself has come under fire for allegedly "whitewashing" a committee report about Duffy's travel expenses.

Coles asked Tkachuk what, specifically, he talked about in conversation with the Prime Minister's office while Duffy's expenses were under scrutiny.

"It's very hard to be specific," Tkachuk said.

It was later revealed that Stephen Harper's chief of staff Nigel Wright gave Duffy a $90,000 cheque, said to be out of Wright's own pocket, to pay back some of Duffy's expenses. 

(Click on the link above for the full interview.)