In the name of Allah, We praise Him, seek His help and ask for His forgiveness. Whoever Allah guides none can misguide, and whoever He allows to fall astray, none can guide them aright. We bear witness that there is none worthy of worship but Allah Alone, and we bear witness that Muhammad (saws) is His slave-servant and the seal of His Messengers.
Allah Says in the Holy Quran Chapter 49 Surah Hujuraat verse 12:
12 O ye who believe! Avoid suspicion as much (as possible): for suspicion in some cases is a sin: and spy not on each other nor speak ill of each other behind their backs.
Islam discourages one to act on doubts or suspicions, but rather one should act only on convictions.
If one is absolutely sure that the food being presented to them is unlawful and ‘haraam’, one should indeed abstain from consuming it.
Even if a believer (Allah forbids) who earns his livelihood from unlawful means, were to offer food to his believing brethren…..the believers who receive the food are not responsible to investigate whether or not the brother who offered them the food earned his wealth from lawful means. The one who earned his livelihood unlawfuly will alone be responsible for his deeds in the Court of Allah Subhanah.
Allow us to relate an example to make the point clearer:
If a father earns his wealth through unlawful means and provides for his family, the father alone will be responsible in the Court of Allah for his transgressions. The food or sustenance which the father provides his family is absolutely lawful for the family, and the family will not be held accountable for the deeds (or misdeeds) of their father in the Presence of their Lord.
Whatever written of Truth and benefit is only due to Allah’s Assistance and Guidance, and whatever of error is of me alone. Allah Alone Knows Best and He is the Only Source of Strength.
Your brother and well wisher in Islam,