Men who climbed over gates to get onto Roker Pier sparked an emergency services alert after fears for their safety.
Sunderland Coastguard Rescue Team, run by HM Coastguard, said they were called to the pier at 6am today after a call was made raising concerns for fishermen on the pier.
A spokesman said: "Police were already on scene on our arrival.
"With the pier gates shut the police stated that up to three persons were on the other side.
"As we were opening the locks for the tunnel access two fishermen were seen to climb back over the pier gate.
"These individuals were handed over to the police, while the team continued to ascertain whether there was a third person.
"The two fishermen, port control and the first informant were consulted again.
"It was ascertained by the team that there was no other individuals on the pier.
"When the pier gates are locked it's a criminal offence contrary to the Port of Sunderland by-laws to enter the pier."
The service has said anyone reporting coastal emergencies should call 999 and ask for the Coastguard.