Is it permissible for a Muslim to have a warehouse business and lease space for the keeping of alcohol products? Is the income from such transaction arrangements Halaal or Haraam?
On another scenario - a Muslim business transporter transports products for its customers. But one of these products is alcohol. Is this permissible?
Allah Ta'ala describes in Surah Al-Maa'idah: Ayat 2 -
"And do not aid in sin and transgression."
Hence, to let one's premises for the above purpose will be assisting in sin and promoting the evils of alcohol.
It is Haraam for a Muslim to transact business, whether directly, as a middle-person, or as a provider of storage facility for alcohol-related businesses. A business owner, being a Muslim must refrain from this. It is also not permissible for a Muslim who owns a shop to rent it to a tenant who will sell alcoholic drinks in it. Under the same principles, refraining from assisting in sin is a major injunction in the life of any Muslim.
As for employees - it is only permissible for them to work in a store which sells alcohol if the major income of the store is not alcohol, but at the same time he will have to try his best to avoid scanning / work involving alcohol, and make effort to look for another job. Thus, if it is a general storage house - he may work there, but if it is a storage house for specific brewery companies (for example) - then it is Haraam to work there.
Any income that is derived from Haram can be purified. Firstly a Muslim should make Taubah and repent for all intentional Haraam business he has involved himself in. He should next dispose the money by giving it as charity to the poor without the intention of obtaining reward. That money for the poor and needy is Halaal.