Is reopening a delivered container a search subject to Fourth Amendment scrutiny even when the police lose sight of the container?

Illinois v. Andreas, supra, 463 U.S. 765, 103 S.Ct. 3319, 77 L.Ed.2d 1003, decided July 5, 1983, adopted a new standard for "controlled deliveries" after contraband is discovered in transit by customs officers. Under Andreas, reopening a delivered container is not a search subject to Fourth Amendment scrutiny even when the police lose sight of the container provided there is no "substantial likelihood that the contents of the container have been changed during the gap in surveillance." (Id., at pp. 3324-3325.)