Police closed the A259 while they dealt with a “high risk” missing person.
The road had to be closed between Friston Pond and East Dean while officers handled the incident.
Pictures showed at least three police cars on the scene.
The road has now re-opened.
A Sussex Police spokesman said: “This was a response to a high-risk missing person, who is now in the care of police. The road has since re-opened.”
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here