Trains between Montrose and Arbroath faced disruption after a safety inspection of the track was carried out on Friday.
Services heading south from Aberdeen towards the central belt were subject to delay.
Disruption lasted until around 10.30am on Friday.
Network Rail confirmed that it had received a report from a train driver of a potential track defect at Lunan Bay near Montrose.
A spokesperson said: “We apologise for the disruption faced by our customers this morning.
“We carried out a track safety inspection between Montrose and Arbroath following feedback from a train driver.
“The track was found to be in good working order and normal services resumed after a short period of delays.”
