Instead, officers politely knocked at the door of a Paulsgrove house this morning as they uncovered a cannabis factory.

Police chose the more formal approach as they were aware a young girl was living in the house and didn't want to frighten her.

Officers entered the property in Stratton Close at 8am today and said they had uncovered a 'significant' number of cannabis plants in an outhouse.

Two people – a man and a woman in their 20s – were arrested.

PC Tony Percival said: 'Within the garden of the premises we located a substantial cannabis factory estimated at around £20,000.

'We have found plants between junior and adult stage of growth in an outdoor summer house.

'Two people have been arrested on suspicion of being concerned in the cultivation of cannabis. I would say from what we have found today they have to have some knowledge of what they are doing just on the amount they have got. It's quite a professional set-up that they have got going here.'

Police said they found about 40 plants in the outhouse and halogen bulbs suspended from the ceiling to help them grow.

Sgt Sean Duffy, from the Cosham Safer Neighbourhood Team, said: 'Early indications are it's a good-size factory.

'A skip will be arriving to take it away.

'We will have to search the property thoroughly but it's a significant factory at the back.'

Police have uncovered several cannabis factories in the city this year.

In September, 330 illegal cannabis plants were discovered in a three-
storey terraced house in Devonshire Square, Southsea.

Neighbours in Stratton Close were shocked by the police raid.
A 25-year-old, who didn't want to be named, said: 'I'm really surprised.

'It's a nice area. There are lovely people around here.

'We don't have nothing to do with anything like that.

'It's just a shame that it has come to that round here.'

A 74-year-old woman, who has lived in the area for more than 20 years, added: 'I'm very surprised – the landlord will be furious. He's a lovely man.'

Police also raided a home opposite and found another £20,000 worth of cannabis plants.