A top Donald Trump supporter suggested Monday that Khizr Khan, the father of a fallen Muslim-American soldier, may belong to the Muslim Brotherhood.

"Mr. Khan more than aggrieved father of a Muslim son — he's Muslim Brotherhood agent helping Hillary," Roger Stone, a former adviser to the Republican presidential nominee, tweeted on Monday morning. Stone linked to an article headlined: "What the media is not telling you about the Muslim who attacked Donald Trump."

Khan delivered an emotional speech at last week's Democratic National Convention, during which he publicly questioned whether Trump has ever read the U.S. Constitution. The father of Capt. Humayun Khan, who died in Iraq, has criticized Trump in subsequent interviews, claiming the GOP presidential hopeful has a "black soul."

The article shared by Stone claims Khan is a "promoter of Islamic Shariah law" who is "working to bring Muslims into the country."

"It is likely that Khan is a Muslim plant working with the Hillary Clinton campaign, probably for the interest of Muslim oil companies as well as Muslim immigration into the U.S.," the author writes.

Stone, who the Trump campaign has long sought to distance themselves from, added in a separate tweet that Khan belongs to the "same radical Muslim group" as Clinton's right-hand woman, Huma Abedin.

Trump found himself embroiled in controversy once again after he responded to Khan's convention speech by questioning why his wife stood silently next to him.

"She probably maybe wasn't allowed to have anything to say," Trump told ABC News' George Stephanopoulos in an interview that aired Saturday.

The billionaire's running mate, Indiana Gov. Mike Pence, appeared to do damage control on Sunday, issuing a statement that claimed he and Trump believe Khan's son "is an American hero and his family, like all Gold Star families, should be cherished by every American."