A cannabis factory in Eastbourne was uncovered by police after a 'strong odour' gave the game away.
According to Sussex Police, officers went to make some enquiries at a property in Cavendish Place, Eastbourne, on Monday at about 9.20am.
They could smell a 'strong odour' of cannabis, the spokesman said, and upon entering and searching the house, they found 350 cannabis plants growing in five rooms.
A man at the property tried to escape up by climbing out of a window onto the roof but was later arrested on suspicion of producing cannabis, police said.
The 21-year-old man was later released without charge and handed over to the immigration authorities.
Inspector Rachel Barrow said: "This was a substantial cannabis factory set up and our enquiries are ongoing to identify those involved. If anyone has any information about it, please contact us."
Contact police online or ring 101 quoting serial 0247 of 01/04 if you can help the investigation.