Today the area is swarming with officers, both plainclothes and uniform, and the block has been cordoned off.

Sandra Andrews, who runs a florist shop opposite, said, “All the people in there are eastern European, mainly Poles and Lithuanians.

“They all seem to get picked up for work early in the morning and dropped off in the evening. Two or three white vans come for them. They may be working in the countryside.

“I had two guys in on Saturday for a bunch of flowers and they sometimes come in for plants. Their English isn’t very good, but we manage.

“When the police arrived, we thought it was a drugs raid, because officers seemed to come out with plants in their hand.”

A neighbour who lives within yards of the block said, “I think there is only one British family in there.

“They seem to be all young eastern European, but they are skilled tradesmen, I think, builders and painters and that sort, very hard working.

“They’ve never been any trouble.

“It’s making everybody round here sick to our stomachs to think what might have happened in there.

“My mother and sisters live in Arbroath and my thoughts have been with them earlier this week. I would never have thought anything like this could happen on my doorstep.”

Another neighbour said “I feel sick. Police took nine of the young Polish people from the block to speak to them in the Damacre Centre.”

In South Esk Street this afternoon, residents gathered on the pavements, stood at their doorways and hung out their windows view the intensifying activity at the flat.

Officers stood at the archway leading into the three-storey whitewashed block as forensic teams in white suits and masks came and went.

At one point a young man in a camouflage jacket was led to a dark car by men in suits.

The building was cordoned off with police tape, while marked cars Were parked outside.

The only signs of life from the building itself were the occasional appearances of residents peering from the upper floor windows.