For regulatory offences like those covered by the POA, in contrast, there is no requirement of mens rea. (ontariocourts.ca)
The accused Society argued that the relevant sections of the Combines Investigation Act were contrary to Sections 7, 11 (a), and 11 (d) of the Charter due to vagueness and the lack of an adequately defined mens rea requirement. (chartercases.com)
As he honestly believed he was entitled to the money in law, he did not have the requisite mens rea for theft, and because proof of theft is a necessary pre-requisite for proof of a robbery, the defendant could not have committed a robbery. (lawteacher.net)