"We have been in constant touch with the appropriate authorities throughout this situation, and will continue to follow the Office of Legislative Services guidelines and counsel in this matter," they said. "While it was our proactive steps that led the investigation to this point, we are appalled at what has transpired."
Cohen, 57, once sponsored a bill creating a computer hotline to report child pornography and other Internet crimes.
Cohen, of Roselle, served in the Assembly from 1990 to 1991 and from 1994 to present. He is now a deputy speaker.
"Both of us have known Neil Cohen for more than two decades," Lesniak and Cryan said. "We know him as a compassionate individual, but if the allegations prove true, clearly there was a side to him neither of us knew. We have been instructed to not make any further comments regarding this very serious matter."
According to two other officials with knowledge of the investigation, who spoke on condition of anonymity because they were not authorized to discuss it, staffers found the pornography on Cohen's computer.
They told state legislative staff, who in turn reported it to the Attorney General's Office, which seized computers from Cohen on Wednesday. He has not been charged, the officials said.
They said Cohen has since been hospitalized for psychiatric treatment.
The investigation was first reported Thursday on the Web site of The Record of Bergen County.