The first day of a sentencing hearing for a navy intelligence officer guilty of espionage has wrapped up with

conflicting accounts on the extent of damage his actions caused.

Sub-Lieutenant Jeffrey Paul Delisle passed information to the Russians from 2007 until 2011 in exchange for close to 72-thousand

dollars.

The Crown called Michelle Tessier, the director general of internal security at C-SIS, who said Delisle’s crimes could mean the

agency receives less intelligence from its sources and allies in the future.

But Wesley Wark, a security expert with the University of Toronto, testified that it would be difficult to determine how much

real damage Delisle may have caused.

Wark says that’s because police intercepted only two attempted transmissions during the almost five years he was selling secrets to the Russians.

Delisle pleaded guilty in October to breach of trust and passing information to a foreign entity that could harm Canada’s interests.

He is the first person to be sentenced under Canada’s Security of Information Act, which was passed after the Sept. 11 attacks.

The hearing continues tomorrow in Halifax provincial court.