As a result, they were opened after a month and given to members of staff. The since-deleted video showed the box of hash brownies, which are thought to have come from Instagram business Dank Bakery.
The text on the video read: “Today almost all the posties in Clapham accidentally ate hash brownies and I had to pick them up one-by-one because they were so high.”
The Royal Mail is taking the matter "very seriously"Matt Cardy/Getty Images
According to the Daily Mail, the clip shows a member of staff staggering towards a trolley in the street.
“Let me take the trolley,” one says, before another added: “You're just really high”.
After it cuts to a staff member saying he’d taken four hash brownies, the text in the video reads: “One guy said he was walking to a door and thought he was walking forever.
“Say a prayer for him right now, hopefully he is asleep or he is singing with unicorns”.
More text read: “We had a delivery of them with no return address and the house was empty and they were in our office for a month so we opened them and they got given out. They were eaten between 5.30-7.30am.”
A Royal Mail spokesperson said an investigation had been launched to find whether 'further action needs to be taken'.
The spokesperson said: “Royal Mail expects the highest standards of behaviour from our people at all times.
“We are taking this matter very seriously. We have commenced an investigation that will determine whether any further action, including disciplinary action, might be taken.
“We are also reminding all staff at the delivery office of the correct procedures for dealing with items with no address for delivery or return.”
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