When he was at his peak, he allegedly got involved in drugs and heroin.

allegedly 是动词 allege 的副词形式，allege 的意思是"声称、宣称"，通常指未经证实的说法。 allegedly 表示"据称、据传"，用于表示某件事是被他人声称的，但尚未被证实或可能存在疑问。