Jeffrey Thompson, in 2010. (C-SPAN)

City filings for two of them — Euclid Street Partners and Real Estate Holdings — list Thompson as the sole member of the companies. The most recent documents for the third, KMJ Development, listed Kweisi Mfume Jr. as the sole member/manager.

Mfume Jr., son of former Maryland congressman Kweisi Mfume, did not return calls and an e-mail prior to the story, but he did get in touch today to say that he no longer owns KMJ Development. In 2009, he said, he sold his minority share in the company to the majority partner: Jeffrey Thompson.

Mfume had no further comment on the donations. Thompson’s attorney, Brendan V. Sullivan Jr., has declined to comment to the Post, citing a policy of not addressing ongoing investigations.

Since 2010, the three Thompson companies have given city candidates a combined $22,000, exclusively in money orders.

But prior to Mfume selling his interest, KMJ Development gave several donations to candidates — including $2,000 apiece to the 2006 mayoral runs of Linda W. Cropp and Adrian M. Fenty and $500 apiece to the 2007 special election campaigns of Yvette M. Alexander, Michael A. Brown and Douglass Sloan — that are listed on campaign finance reports as checks, not money orders.

The subsequent money orders went to Vincent C. Gray’s 2010 mayoral campaign, Harry Thomas Jr.’s 2010 re-election campaign and Vincent Orange’s 2011 at-large council campaign.

One question federal prosecutors are likely to be asking KMJ’s current owner: Why give with money orders in 2010 and 2011 when, not three years earlier, the company had an active checking account?

And another question: If cash was used to buy money orders for the businesses, where did it come from?

Property records show each company has or has had property holdings in the city. JT Real Estate Holdings owns an unused parcel adjacent to the Poplar Point site eyed for redevelopment; KMJ and Euclid Street Partners owned houses in the city until recent months.