Lacroix spoke to CBC Halifax host Tom Murphy on Wednesday, following a report by the Toronto Star that alleged Solomon had secretive business dealings in the art world with people he had dealt with in his role as a journalist.
Lacroix said he wasn't in a position to discuss the case in "an open way" but said that after receiving information Monday and conducting an internal review, CBC found there was a breach of both the conflict of interest and ethics policies, as well as journalistic standards.
"We moved extremely quickly and decisively because Canadians have to trust the integrity of our journalism and that's the announcement that we made yesterday," Lacroix said.
CBC News editor in chief Jennifer McGuire said in a note to staff Wednesday that Solomon disclosed in April that a company he and his wife owned "had a business partnership with an art dealer."
"We told him, and he assured us, this could not in any way conflict with his work for CBC News," McGuire's note said.
McGuire said a Toronto Star reporter approached CBC on Monday with information which "if true, significantly changed our understanding of the situation" and that on Tuesday, based on information from a CBC review, the decision was made to "discontinue our relationship" with Solomon.
The decision was made prior to the publication of the report in the Star, McGuire said in her note.
"Yesterday, we took the steps necessary to protect the integrity of our colleagues and the service we provide to Canadians," she said.
Solomon said in a statement released Tuesday that he formed a private business partnership in 2013 to broker Canadian art and that he had disclosed the business to CBC "earlier this year."
The former host of CBC's flagship political and radio programs said he didn't view the art business "as a conflict with my political journalism at the CBC and never intentionally used my position at the CBC to promote the business."
Solomon, who had worked in many roles at CBC since 1994, said he was "deeply sorry" for any damage his business had caused and that he has "the utmost respect for the CBC and what it stands for."