A claim on the Internet that a San Francisco sheriff’s deputy is responsible for injuring Iraq War veteran Scott Olsen last Tuesday night during a clash between Occupy Oakland protesters and police is groundless, a spokeswoman for the San Francisco Sheriff’s Office said Monday.

A picture of the deputy, his photo and video of him on downtown Oakland streets last Tuesday night has gone viral with hundreds, if not thousands of Twitter messages, a posting on Facebook and on numerous websites.

“We have seen what everyone else has seen on the Internet,” said spokeswoman Eileen Hirst. “So, we’re investigating. However, we’re quite certain that anyone involved with our department was not responsible for anything that hit Mr. Olsen.” Hirst said the department is treating the Internet debate as a citizen’s complaint and is investigating.

Between the pre-dawn raid on the Occupy Oakland camp at Frank Ogawa Plaza last Tuesday and the after-dark clashes between police and the hundreds of protesters, 17 police agencies, including the Oakland Police Department, were involved in police action.

Olsen, 24, of Daly City, suffered a skull fracture and is at an area hospital. He is expected to make a full recovery.

His face and head were covered in blood seconds after tear-gas canisters and other explosive devices, which emitted smoke and caused the hundreds of protesters to scramble, went off on Broadway where Olsen way rallying.

Doctors have not confirmed Olsen was hit in the head with a tear-gas canister, but Alden Harken, chair of surgery at Highland Hospital, where Olsen was first treated, said, “It would have taken a moderate amount of energy to fracture your skull.”

As the smoke is wafting into the air and protesters are seen running, at least four people are shown on video screaming “medic, medic, medic” as they come to his aid. They asked for his name, but he did not speak or say what happened. Video also shows an officer behind a barricade throwing an explosive canister, it is not clear what, into the crowd. The name of that officer has not been released.

Olsen was not the only one injured last Tuesday; others were hit by projectiles and overcome with tear-gas.

“It’s extremely unfortunate when one deputy has been singled out when no agency has determined what exactly happened,” Hirst said.

During the evening protest, Interim Chief Howard Jordan, said officers were assaulted, doused with hazardous materials and hit with large rocks and bottles, which resulted in police calling an unlawful assembly and orders to disperse. He said Oakland police used bean bags and gas but do not use rubber bullets or wooden dowels. It is possible that other agencies did, he said.

The Oakland Tribune has requested that each agency provide the number of officers on scene, what their role was, where they were stationed and if they used nonlethal weapons. Every agency that had officers there, except the Solano County Sheriff’s Office and the Santa Clara County Sheriff’s Office, has responded to the request. All said none of their officers used nonlethal force.

San Jose Police sent 30 motor officers for crowd control.

The only nonlethal weapons San Francisco sheriff deputies brought to Oakland were two Anti-Riot Weapon Enfield rifles that fire 37 mm nonlethal rounds, similar to a roll of quarters. However, no deputies shot those weapons Tuesday night, Hirst said. Asked if someone from another department could have fired a deputy’s weapon, Hirst said, “No, we can’t use equipment we’re not trained in.”

At least 75 uniformed officers from the CHP were keeping motorists off Interstates 880 and 980, protecting state buildings on Clay Street and doing traffic control. CHP Officers did not use any nonlethal force. One CHP patrol car parked at 16th and Broadway was damaged by protesters with rear and side windows busted out. One officer had bottles thrown at him, but was not injured, a spokesman said.