LONDON (AP) — Prosecutors have dropped charges against two Canadian pilots accused of preparing to fly a commercial aircraft while under the influence of alcohol after their blood samples were mistakenly destroyed at a Scottish prison.

Prosecutors say there will be no further action against Imran Syed, 39, and Jean-Francois Perreault, 41, who were arrested July 18, 2016, before they were to pilot an Air Transat flight from Glasgow to Toronto.

Authorities say Syed, from Toronto, allegedly had 49 milligrams of alcohol in 100 milliliters of blood. Perreault, from the province of Ontario, allegedly had 32 milligrams.

Both men denied the charges.

The flight eventually took off with a different crew the next morning after about 250 passengers spent the night at hotels.

"We are working with Police Scotland to ensure there are proper processes and guidance in place covering the retention and storage of samples when an accused person is remanded in custody," prosecutors said.

Air Transat had suspended the pilots but they will be reinstated because they have been "declared innocent," the airline said.

"We will be meeting with them in the next few days to plan their reinstatement since there is no charge against them and we have no evidence that they have broken any law nor our internal rules," the airline said. "They will need to undergo retraining and requalification as per applicable legislation, and we will put in place measures to ensure that their behavior is exemplary."